cmd/internal/gc: move componentgen into portable code

Change-Id: I652cc7a33a186d1041f62f6e7581421496832a27
Reviewed-on: https://go-review.googlesource.com/7747
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
diff --git a/src/cmd/8g/ggen.go b/src/cmd/8g/ggen.go
index 077b657..3a197cd 100644
--- a/src/cmd/8g/ggen.go
+++ b/src/cmd/8g/ggen.go
@@ -112,7 +112,7 @@
 	w := uint32(nl.Type.Width)
 
 	// Avoid taking the address for simple enough types.
-	if componentgen(nil, nl) {
+	if gc.Componentgen(nil, nl) {
 		return
 	}