cmd/cgo, go/build: finish a cleanup TODO

Removing #cgo directive parsing from cmd/cgo was done in
https://golang.org/cl/8610044.

Change-Id: Id1bec58c6ec1f932df0ce0ee84ff253655bb73ff
Reviewed-on: https://go-review.googlesource.com/2501Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/cgo/gcc.go

@@ -154,20 +154,6 @@ func splitQuoted(s string) (r []string, err error) {
 	return args, err
 }
 
-var safeBytes = []byte(`+-.,/0123456789:=ABCDEFGHIJKLMNOPQRSTUVWXYZ\_abcdefghijklmnopqrstuvwxyz`)
-
-func safeName(s string) bool {
-	if s == "" {
-		return false
-	}
-	for i := 0; i < len(s); i++ {
-		if c := s[i]; c < 0x80 && bytes.IndexByte(safeBytes, c) < 0 {
-			return false
-		}
-	}
-	return true
-}
-
 // Translate rewrites f.AST, the original Go input, to remove
 // references to the imported package C, replacing them with
 // references to the equivalent Go types, functions, and variables.

src/go/build/build.go

@@ -1073,9 +1073,6 @@ func (ctxt *Context) shouldBuild(content []byte, allTags map[string]bool) bool {
 // saveCgo saves the information from the #cgo lines in the import "C" comment.
 // These lines set CFLAGS, CPPFLAGS, CXXFLAGS and LDFLAGS and pkg-config directives
 // that affect the way cgo's C code is built.
-//
-// TODO(rsc): This duplicates code in cgo.
-// Once the dust settles, remove this code from cgo.
 func (ctxt *Context) saveCgo(filename string, di *Package, cg *ast.CommentGroup) error {
 	text := cg.Text()
 	for _, line := range strings.Split(text, "\n") {