cmd/compile: remove compiling_wrappers

It's no longer needed after removing safemode.

Change-Id: I7581d77a86342e3b6d7c632839f5eb7a5c20902e
Reviewed-on: https://go-review.googlesource.com/c/143397
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -208,8 +208,6 @@ var compiling_runtime bool
 // Compiling the standard library
 var compiling_std bool
 
-var compiling_wrappers bool
-
 var use_writebarrier bool
 
 var pure_go bool

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

@@ -406,18 +406,14 @@ func methods(t *types.Type) []*Sig {
 		if !sig.isym.Siggen() {
 			sig.isym.SetSiggen(true)
 			if !types.Identical(this, it) {
-				compiling_wrappers = true
 				genwrapper(it, f, sig.isym)
-				compiling_wrappers = false
 			}
 		}
 
 		if !sig.tsym.Siggen() {
 			sig.tsym.SetSiggen(true)
 			if !types.Identical(this, t) {
-				compiling_wrappers = true
 				genwrapper(t, f, sig.tsym)
-				compiling_wrappers = false
 			}
 		}
 	}