cmd/gc: fix PkgPath of byte, rune types

Fixes #3853.

R=ken2
CC=golang-dev
https://golang.org/cl/6492071
diff --git a/src/pkg/reflect/all_test.go b/src/pkg/reflect/all_test.go
index 3b6fd5e..148db88 100644
--- a/src/pkg/reflect/all_test.go
+++ b/src/pkg/reflect/all_test.go
@@ -1384,7 +1384,30 @@
 		path string
 	}{
 		{TypeOf(&base64.Encoding{}).Elem(), "encoding/base64"},
+		{TypeOf(int(0)), ""},
+		{TypeOf(int8(0)), ""},
+		{TypeOf(int16(0)), ""},
+		{TypeOf(int32(0)), ""},
+		{TypeOf(int64(0)), ""},
 		{TypeOf(uint(0)), ""},
+		{TypeOf(uint8(0)), ""},
+		{TypeOf(uint16(0)), ""},
+		{TypeOf(uint32(0)), ""},
+		{TypeOf(uint64(0)), ""},
+		{TypeOf(uintptr(0)), ""},
+		{TypeOf(float32(0)), ""},
+		{TypeOf(float64(0)), ""},
+		{TypeOf(complex64(0)), ""},
+		{TypeOf(complex128(0)), ""},
+		{TypeOf(byte(0)), ""},
+		{TypeOf(rune(0)), ""},
+		{TypeOf([]byte(nil)), ""},
+		{TypeOf([]rune(nil)), ""},
+		{TypeOf(string("")), ""},
+		{TypeOf((*interface{})(nil)).Elem(), ""},
+		{TypeOf((*byte)(nil)), ""},
+		{TypeOf((*rune)(nil)), ""},
+		{TypeOf((*int64)(nil)), ""},
 		{TypeOf(map[string]int{}), ""},
 		{TypeOf((*error)(nil)).Elem(), ""},
 	}