libtest: Add regression tests for padding

As you can see the padding is wrong when running benches as tests. This
will be fixed in the next commit. (Benches should only be padded when
run as benches to make it easy to compare the benchmark numbers.)

tests/run-make/libtest-padding/Makefile

@@ -0,0 +1,14 @@
+# ignore-cross-compile because we run the compiled code
+# needs-unwind because #[bench] and -Cpanic=abort requires -Zpanic-abort-tests
+include ../tools.mk
+
+NORMALIZE=sed 's%[0-9,]\+ ns/iter (+/- [0-9,]\+)%?? ns/iter (+/- ??)%' | sed 's%finished in [0-9\.]\+%finished in ??%'
+
+all:
+	$(RUSTC) --test tests.rs
+
+	$(call RUN,tests) --test-threads=1 | $(NORMALIZE) > "$(TMPDIR)"/test.stdout
+	$(RUSTC_TEST_OP) "$(TMPDIR)"/test.stdout test.stdout
+
+	$(call RUN,tests) --test-threads=1 --bench | $(NORMALIZE) > "$(TMPDIR)"/bench.stdout
+	$(RUSTC_TEST_OP) "$(TMPDIR)"/bench.stdout bench.stdout

tests/run-make/libtest-padding/bench.stdout

@@ -0,0 +1,9 @@
+
+running 4 tests
+test short_test_name ... ignored
+test this_is_a_really_long_test_name ... ignored
+test short_bench_name                 ... bench:           ?? ns/iter (+/- ??)
+test this_is_a_really_long_bench_name ... bench:           ?? ns/iter (+/- ??)
+
+test result: ok. 0 passed; 0 failed; 2 ignored; 2 measured; 0 filtered out; finished in ??s
+

tests/run-make/libtest-padding/test.stdout

@@ -0,0 +1,9 @@
+
+running 4 tests
+test short_bench_name                 ... ok
+test short_test_name ... ok
+test this_is_a_really_long_bench_name ... ok
+test this_is_a_really_long_test_name ... ok
+
+test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in ??s
+

tests/run-make/libtest-padding/tests.rs

@@ -0,0 +1,18 @@
+#![feature(test)]
+extern crate test;
+
+#[test]
+fn short_test_name() {}
+
+#[test]
+fn this_is_a_really_long_test_name() {}
+
+#[bench]
+fn short_bench_name(b: &mut test::Bencher) {
+    b.iter(|| 1);
+}
+
+#[bench]
+fn this_is_a_really_long_bench_name(b: &mut test::Bencher) {
+    b.iter(|| 1);
+}