x/tools: delete x/tools/go/types and dependent packages/client files

Per https://groups.google.com/forum/#!topic/golang-announce/qu_rAphYdxY
this change deletes the packages

  go/exact
  go/gccgoimporter
  go/gcimporter
  go/importer
  go/types
  cmd/vet

from the x/tools repo and any files depending on those packages
building against Go 1.4.

x/tools packages depending on any of these libraries must use the
respective versions from the std lib or use vendored versions if
building against 1.4.

Remaining packages may or may not build against Go 1.4 anymore
and will not be supported against 1.4.

Change-Id: I1c655fc30aee49b6c7326ebd4eb1bb0836ac97e0
Reviewed-on: https://go-review.googlesource.com/20810
Reviewed-by: Alan Donovan <adonovan@google.com>
diff --git a/cmd/godex/gccgo.go b/cmd/godex/gccgo.go
index 2f2168d..785441c 100644
--- a/cmd/godex/gccgo.go
+++ b/cmd/godex/gccgo.go
@@ -9,34 +9,28 @@
 package main
 
 import (
-	"golang.org/x/tools/go/gccgoimporter"
-	"golang.org/x/tools/go/types"
-)
-
-var (
-	initmap = make(map[*types.Package]gccgoimporter.InitData)
+	"go/importer"
+	"go/types"
 )
 
 func init() {
-	incpaths := []string{"/"}
-
-	// importer for default gccgo
-	var inst gccgoimporter.GccgoInstallation
-	inst.InitFromDriver("gccgo")
-	register("gccgo", inst.GetImporter(incpaths, initmap))
+	register("gccgo", importer.For("gccgo", nil))
 }
 
 // Print the extra gccgo compiler data for this package, if it exists.
 func (p *printer) printGccgoExtra(pkg *types.Package) {
-	if initdata, ok := initmap[pkg]; ok {
-		p.printf("/*\npriority %d\n", initdata.Priority)
+	// Disabled for now.
+	// TODO(gri) address this at some point.
 
-		p.printDecl("init", len(initdata.Inits), func() {
-			for _, init := range initdata.Inits {
-				p.printf("%s %s %d\n", init.Name, init.InitFunc, init.Priority)
-			}
-		})
+	// if initdata, ok := initmap[pkg]; ok {
+	// 	p.printf("/*\npriority %d\n", initdata.Priority)
 
-		p.print("*/\n")
-	}
+	// 	p.printDecl("init", len(initdata.Inits), func() {
+	// 		for _, init := range initdata.Inits {
+	// 			p.printf("%s %s %d\n", init.Name, init.InitFunc, init.Priority)
+	// 		}
+	// 	})
+
+	// 	p.print("*/\n")
+	// }
 }