A couple of fixes for using Makefile.standalone on Mac.

src/IceTargetLoweringX8632.cpp

Index: src/IceTargetLoweringX8632.cpp
diff --git a/src/IceTargetLoweringX8632.cpp b/src/IceTargetLoweringX8632.cpp
index 8123e74c31ef9b2f0624fb40891f07fdef59b093..7c60d085783ff9d51af611a955c1a8189ca36ff4 100644
--- a/src/IceTargetLoweringX8632.cpp
+++ b/src/IceTargetLoweringX8632.cpp
@@ -143,7 +143,7 @@ IceString typeIdentString(const Type Ty) {
 // could get out of sync if enum values are reordered or if entries
 // are added or deleted.  This dummy function uses static_assert to
 // ensure everything is kept in sync.
-void xMacroIntegrityCheck() {
+void __attribute__((unused)) xMacroIntegrityCheck() {
   // Validate the enum values in FCMPX8632_TABLE.
   {
     // Define a temporary set of enum values based on low-level