Update f16 and f128 tests to run on both 2015 and 2018 editions

Reproduce the bug from <https://github.com/rust-lang/rust/issues/123282>
that indicates this feature gate hits edition-dependent resolution paths.
Resolution changed in edition 2018, so test that as well.

tests/ui/feature-gates/feature-gate-f128.e2015.stderr

@@ -1,5 +1,5 @@
 error[E0658]: the type `f128` is unstable
-  --> $DIR/feature-gate-f128.rs:3:10
+  --> $DIR/feature-gate-f128.rs:11:10
    |
 LL | const A: f128 = 10.0;
    |          ^^^^
@@ -9,7 +9,7 @@ LL | const A: f128 = 10.0;
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f128` is unstable
-  --> $DIR/feature-gate-f128.rs:6:12
+  --> $DIR/feature-gate-f128.rs:14:12
    |
 LL |     let a: f128 = 100.0;
    |            ^^^^
@@ -19,7 +19,7 @@ LL |     let a: f128 = 100.0;
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f128` is unstable
-  --> $DIR/feature-gate-f128.rs:11:11
+  --> $DIR/feature-gate-f128.rs:19:11
    |
 LL | fn foo(a: f128) {}
    |           ^^^^
@@ -29,7 +29,7 @@ LL | fn foo(a: f128) {}
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f128` is unstable
-  --> $DIR/feature-gate-f128.rs:14:8
+  --> $DIR/feature-gate-f128.rs:22:8
    |
 LL |     a: f128,
    |        ^^^^
@@ -39,7 +39,7 @@ LL |     a: f128,
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f128` is unstable
-  --> $DIR/feature-gate-f128.rs:7:13
+  --> $DIR/feature-gate-f128.rs:15:13
    |
 LL |     let b = 0.0f128;
    |             ^^^^^^^

tests/ui/feature-gates/feature-gate-f128.e2018.stderr

@@ -0,0 +1,53 @@
+error[E0658]: the type `f128` is unstable
+  --> $DIR/feature-gate-f128.rs:11:10
+   |
+LL | const A: f128 = 10.0;
+   |          ^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f128)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f128` is unstable
+  --> $DIR/feature-gate-f128.rs:14:12
+   |
+LL |     let a: f128 = 100.0;
+   |            ^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f128)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f128` is unstable
+  --> $DIR/feature-gate-f128.rs:19:11
+   |
+LL | fn foo(a: f128) {}
+   |           ^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f128)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f128` is unstable
+  --> $DIR/feature-gate-f128.rs:22:8
+   |
+LL |     a: f128,
+   |        ^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f128)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f128` is unstable
+  --> $DIR/feature-gate-f128.rs:15:13
+   |
+LL |     let b = 0.0f128;
+   |             ^^^^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f128)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/feature-gates/feature-gate-f128.rs

@@ -1,3 +1,7 @@
+//@ revisions: e2015 e2018
+//
+//@[e2018] edition:2018
+
 #![allow(unused)]
 
 const A: f128 = 10.0; //~ ERROR the type `f128` is unstable

tests/ui/feature-gates/feature-gate-f16.e2015.stderr

@@ -1,5 +1,5 @@
 error[E0658]: the type `f16` is unstable
-  --> $DIR/feature-gate-f16.rs:3:10
+  --> $DIR/feature-gate-f16.rs:11:10
    |
 LL | const A: f16 = 10.0;
    |          ^^^
@@ -9,7 +9,7 @@ LL | const A: f16 = 10.0;
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f16` is unstable
-  --> $DIR/feature-gate-f16.rs:6:12
+  --> $DIR/feature-gate-f16.rs:14:12
    |
 LL |     let a: f16 = 100.0;
    |            ^^^
@@ -19,7 +19,7 @@ LL |     let a: f16 = 100.0;
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f16` is unstable
-  --> $DIR/feature-gate-f16.rs:11:11
+  --> $DIR/feature-gate-f16.rs:19:11
    |
 LL | fn foo(a: f16) {}
    |           ^^^
@@ -29,7 +29,7 @@ LL | fn foo(a: f16) {}
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f16` is unstable
-  --> $DIR/feature-gate-f16.rs:14:8
+  --> $DIR/feature-gate-f16.rs:22:8
    |
 LL |     a: f16,
    |        ^^^
@@ -39,7 +39,7 @@ LL |     a: f16,
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: the type `f16` is unstable
-  --> $DIR/feature-gate-f16.rs:7:13
+  --> $DIR/feature-gate-f16.rs:15:13
    |
 LL |     let b = 0.0f16;
    |             ^^^^^^

tests/ui/feature-gates/feature-gate-f16.e2018.stderr

@@ -0,0 +1,53 @@
+error[E0658]: the type `f16` is unstable
+  --> $DIR/feature-gate-f16.rs:11:10
+   |
+LL | const A: f16 = 10.0;
+   |          ^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f16)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f16` is unstable
+  --> $DIR/feature-gate-f16.rs:14:12
+   |
+LL |     let a: f16 = 100.0;
+   |            ^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f16)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f16` is unstable
+  --> $DIR/feature-gate-f16.rs:19:11
+   |
+LL | fn foo(a: f16) {}
+   |           ^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f16)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f16` is unstable
+  --> $DIR/feature-gate-f16.rs:22:8
+   |
+LL |     a: f16,
+   |        ^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f16)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: the type `f16` is unstable
+  --> $DIR/feature-gate-f16.rs:15:13
+   |
+LL |     let b = 0.0f16;
+   |             ^^^^^^
+   |
+   = note: see issue #116909 <https://github.com/rust-lang/rust/issues/116909> for more information
+   = help: add `#![feature(f16)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 5 previous errors
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/feature-gates/feature-gate-f16.rs

@@ -1,3 +1,7 @@
+//@ revisions: e2015 e2018
+//
+//@[e2018] edition:2018
+
 #![allow(unused)]
 
 const A: f16 = 10.0; //~ ERROR the type `f16` is unstable

tests/ui/resolve/primitive-f16-f128-shadowed-mod.rs

@@ -0,0 +1,19 @@
+//@ compile-flags: --crate-type=lib
+//@ check-pass
+//@ revisions: e2015 e2018
+//
+//@[e2018] edition:2018
+
+// Verify that gates for the `f16` and `f128` features do not apply to user modules
+// See <https://github.com/rust-lang/rust/issues/123282>
+
+mod f16 {
+    pub fn a16() {}
+}
+
+mod f128 {
+    pub fn a128() {}
+}
+
+pub use f128::a128;
+pub use f16::a16;

tests/ui/resolve/primitive-f16-f128-shadowed.rs

@@ -1,5 +1,8 @@
 //@ compile-flags: --crate-type=lib
 //@ check-pass
+//@ revisions: e2015 e2018
+//
+//@[e2018] edition:2018
 
 // Verify that gates for the `f16` and `f128` features do not apply to user types