Use llvm-{strip,objcopy} by default

... except for Darwin Mach-O, as it is not supported by llvm-strip.

Test: m checkbuild
Bug: 119221035
Change-Id: I021637b6dd3530bff1f563f2ec7c2168e1083b7e
diff --git a/cc/builder.go b/cc/builder.go
index 645b3c2..6e24d56 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -255,7 +255,7 @@
 	stripKeepSymbols       bool
 	stripKeepMiniDebugInfo bool
 	stripAddGnuDebuglink   bool
-	stripUseLlvmStrip      bool
+	stripUseGnuStrip       bool
 
 	protoDeps        android.Paths
 	protoFlags       string
@@ -821,8 +821,8 @@
 	if flags.stripKeepSymbols {
 		args += " --keep-symbols"
 	}
-	if flags.stripUseLlvmStrip {
-		args += " --use-llvm-strip"
+	if flags.stripUseGnuStrip {
+		args += " --use-gnu-strip"
 	}
 
 	ctx.Build(pctx, android.BuildParams{