Subzero: Add -Wshadow to the build.

src/IceGlobalInits.cpp

Index: src/IceGlobalInits.cpp
diff --git a/src/IceGlobalInits.cpp b/src/IceGlobalInits.cpp
index c95456c6421af516bc67a66cc6f001a25cf5353b..f6e4450e4cc1b6bf53d0172d157c7e7991bc5732 100644
--- a/src/IceGlobalInits.cpp
+++ b/src/IceGlobalInits.cpp
@@ -19,9 +19,14 @@
 #include "IceDefs.h"
 #include "IceGlobalContext.h"
 #include "IceTypes.h"
+
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-parameter"
+#pragma clang diagnostic ignored "-Wshadow"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/Value.h"
+#pragma clang diagnostic ignored "-Wshadow"
 
 namespace {
 char hexdigit(unsigned X) { return X < 10 ? '0' + X : 'A' + X - 10; }