Subzero: Add -Wshadow to the build.

src/IceRegAlloc.h

Index: src/IceRegAlloc.h
diff --git a/src/IceRegAlloc.h b/src/IceRegAlloc.h
index 1658a7d4d97e27468ce1e183929e681f00fd5d2f..8bb137e7acdb85395faacf956960ec374761a74b 100644
--- a/src/IceRegAlloc.h
+++ b/src/IceRegAlloc.h
@@ -27,10 +27,10 @@ class LinearScan {
   LinearScan &operator=(const LinearScan &) = delete;
 
 public:
-  explicit LinearScan(Cfg *Func) : Func(Func) {}
+  explicit LinearScan(Cfg *MyFunc) : Func(MyFunc) {}
   void init(RegAllocKind Kind);
   void scan(const llvm::SmallBitVector &RegMask, bool Randomized);
-  void dump(Cfg *Func) const;
+  void dump() const;
 
 private:
   typedef std::vector<Variable *> OrderedRanges;