Replacing HUGE_VALF with llvm::huge_valf in order to work around a warning triggered in MSVC 12.

Patch reviewed by Reid Kleckner and Jim Grosbach.

llvm-svn: 194533
diff --git a/llvm/lib/CodeGen/Spiller.cpp b/llvm/lib/CodeGen/Spiller.cpp
index d72c596..d5b3a4a 100644
--- a/llvm/lib/CodeGen/Spiller.cpp
+++ b/llvm/lib/CodeGen/Spiller.cpp
@@ -77,7 +77,7 @@
 
     DEBUG(dbgs() << "Spilling everywhere " << *li << "\n");
 
-    assert(li->weight != HUGE_VALF &&
+    assert(li->weight != llvm::huge_valf &&
            "Attempting to spill already spilled value.");
 
     assert(!TargetRegisterInfo::isStackSlot(li->reg) &&