cmd/cgo, cmd/compile, cmd/link: remove old style build tags

The minimum bootstrap version for Go ≥ 1.20 is Go 1.17. That version
supports the new style //go:build lines. Thus the old style //+build
lines can be dropped in this part of the tree as well. Leave the
//+build lines in cmd/dist which will ensure the minimum Go version
during bootstrap.

As suggested by Cherry during review of CL 430496

For #44505

Change-Id: If53c0b02cacbfb055a33e73cfd38578dfd3aa340
Reviewed-on: https://go-review.googlesource.com/c/go/+/436915
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>

src/cmd/cgo/ast_go1.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build compiler_bootstrap
-// +build compiler_bootstrap
 
 package main
 

src/cmd/cgo/ast_go118.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !compiler_bootstrap
-// +build !compiler_bootstrap
 
 package main
 

src/cmd/compile/internal/base/bootstrap_false.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !compiler_bootstrap
-// +build !compiler_bootstrap
 
 package base
 

src/cmd/compile/internal/base/bootstrap_true.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build compiler_bootstrap
-// +build compiler_bootstrap
 
 package base
 

src/cmd/compile/internal/base/mapfile_mmap.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || (solaris && go1.20)
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris,go1.20
 
 package base
 

src/cmd/compile/internal/base/mapfile_read.go

@@ -3,13 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !(solaris && go1.20)
-// +build !darwin
-// +build !dragonfly
-// +build !freebsd
-// +build !linux
-// +build !netbsd
-// +build !openbsd
-// +build !solaris !go1.20
 
 package base
 

src/cmd/compile/internal/ir/mknode.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 // Note: this program must be run in this directory.
 //   go run mknode.go

src/cmd/compile/internal/ssa/flags_test.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build amd64 || arm64
-// +build amd64 arm64
 
 package ssa
 

src/cmd/compile/internal/ssa/gen/386Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/AMD64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/ARM64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/ARMOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/LOONG64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/MIPS64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/MIPSOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/PPC64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/RISCV64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/S390XOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/WasmOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/dec64Ops.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/decOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/genericOps.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 package main
 

src/cmd/compile/internal/ssa/gen/main.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 // The gen command generates Go code (in the parent directory) for all
 // the architecture-specific opcodes, blocks, and rewrites.

src/cmd/compile/internal/ssa/gen/rulegen.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build gen
-// +build gen
 
 // This program generates Go code that applies rewrite rules to a Value.
 // The generated code implements a function of type func (v *Value) bool

src/cmd/compile/internal/typecheck/builtin/runtime.go

@@ -7,7 +7,6 @@
 // to avoid depending on having a working compiler binary.
 
 //go:build ignore
-// +build ignore
 
 package runtime
 

src/cmd/compile/internal/typecheck/mkbuiltin.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build ignore
-// +build ignore
 
 // Generate builtin.go from builtin/runtime.go.
 

src/cmd/compile/internal/types2/example_test.go

@@ -6,7 +6,6 @@
 // access to compiled packages for import.
 //
 //go:build !arm && !arm64
-// +build !arm,!arm64
 
 package types2_test
 

src/cmd/internal/bio/buf_mmap.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || (solaris && go1.20)
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris,go1.20
 
 package bio
 

src/cmd/internal/bio/buf_nommap.go

@@ -3,13 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !(solaris && go1.20)
-// +build !darwin
-// +build !dragonfly
-// +build !freebsd
-// +build !linux
-// +build !netbsd
-// +build !openbsd
-// +build !solaris !go1.20
 
 package bio
 

src/cmd/link/elf_test.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build dragonfly || freebsd || linux || netbsd || openbsd
-// +build dragonfly freebsd linux netbsd openbsd
 
 package main
 

src/cmd/link/internal/ld/outbuf_mmap.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || (solaris && go1.20)
-// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris,go1.20
 
 package ld
 

src/cmd/link/internal/ld/outbuf_nofallocate.go

@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !darwin && !linux
-// +build !darwin,!linux
 
 package ld
 

src/cmd/link/internal/ld/outbuf_nommap.go

@@ -3,15 +3,6 @@
 // license that can be found in the LICENSE file.
 
 //go:build !aix && !darwin && !dragonfly && !freebsd && !linux && !netbsd && !openbsd && !(solaris && go1.20) && !windows
-// +build !aix
-// +build !darwin
-// +build !dragonfly
-// +build !freebsd
-// +build !linux
-// +build !netbsd
-// +build !openbsd
-// +build !solaris !go1.20
-// +build !windows
 
 package ld