cmd/compile: remove unused importimport function

Functionality is present in bimport.go in slightly modified form.

Change-Id: I6be79d91588873e6ba70d6ab07ba2caa12346dfc
Reviewed-on: https://go-review.googlesource.com/27672Reviewed-by: Matthew Dempsky <mdempsky@google.com>

src/cmd/compile/internal/gc/bimport.go

@@ -212,6 +212,12 @@ func (p *importer) verifyTypes() {
 	}
 }
 
+// numImport tracks how often a package with a given name is imported.
+// It is used to provide a better error message (by using the package
+// path to disambiguate) if a package that appears multiple times with
+// the same name appears in an error message.
+var numImport = make(map[string]int)
+
 func (p *importer) pkg() *Pkg {
 	// if the package was seen before, i is its index (>= 0)
 	i := p.tagOrIndex()
@@ -244,7 +250,7 @@ func (p *importer) pkg() *Pkg {
 		Fatalf("importer: package path %q for pkg index %d", path, len(p.pkgList))
 	}
 
-	// see importimport (export.go)
+	// add package to pkgList
 	pkg := importpkg
 	if path != "" {
 		pkg = mkpkg(path)

src/cmd/compile/internal/gc/export.go

@@ -295,34 +295,6 @@ func pkgtype(s *Sym) *Type {
 	return s.Def.Type
 }
 
-// numImport tracks how often a package with a given name is imported.
-// It is used to provide a better error message (by using the package
-// path to disambiguate) if a package that appears multiple times with
-// the same name appears in an error message.
-var numImport = make(map[string]int)
-
-func importimport(s *Sym, path string) {
-	// Informational: record package name
-	// associated with import path, for use in
-	// human-readable messages.
-
-	if isbadimport(path) {
-		errorexit()
-	}
-	p := mkpkg(path)
-	if p.Name == "" {
-		p.Name = s.Name
-		numImport[s.Name]++
-	} else if p.Name != s.Name {
-		Yyerror("conflicting names %s and %s for package %q", p.Name, s.Name, p.Path)
-	}
-
-	if incannedimport == 0 && myimportpath != "" && path == myimportpath {
-		Yyerror("import %q: package depends on %q (import cycle)", importpkg.Path, path)
-		errorexit()
-	}
-}
-
 // importconst declares symbol s as an imported constant with type t and value n.
 func importconst(s *Sym, t *Type, n *Node) {
 	importsym(s, OLITERAL)