Move some make variables from GNU binutils to LLVM equivalents.

There are others still to look at, but this set doesn't seem to break
anything for me.

Bug: http://b/147452927
Test: treehugger
Change-Id: I794684e23eee1326deb34bb4d5ed5831a47b8fa3
diff --git a/cc/makevars.go b/cc/makevars.go
index 48d5636..923472a 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -280,9 +280,9 @@
 		ctx.Strict(makePrefix+"STRIP", "${config.MacStripPath}")
 	} else {
 		ctx.Strict(makePrefix+"AR", "${config.ClangBin}/llvm-ar")
-		ctx.Strict(makePrefix+"READELF", gccCmd(toolchain, "readelf"))
-		ctx.Strict(makePrefix+"NM", gccCmd(toolchain, "nm"))
-		ctx.Strict(makePrefix+"STRIP", gccCmd(toolchain, "strip"))
+		ctx.Strict(makePrefix+"READELF", "${config.ClangBin}/llvm-readelf")
+		ctx.Strict(makePrefix+"NM", "${config.ClangBin}/llvm-nm")
+		ctx.Strict(makePrefix+"STRIP", "${config.ClangBin}/llvm-strip")
 	}
 
 	if target.Os.Class == android.Device {