Fix issues with compiling V8 with LLVM Clang...

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
===================================================================
--- src/x64/macro-assembler-x64.cc	(revision 4110)
+++ src/x64/macro-assembler-x64.cc	(working copy)
@@ -197,9 +197,9 @@
   // avoid having the fast case for smis leave the registers
   // unchanged.
   if (FLAG_debug_code) {
-    movq(object, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
-    movq(value, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
-    movq(smi_index, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(smi_index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
   }
 }
 
@@ -270,9 +270,9 @@
   // Clobber all input registers when running with the debug-code flag
   // turned on to provoke errors.
   if (FLAG_debug_code) {
-    movq(object, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
-    movq(scratch, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
-    movq(smi_index, bit_cast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(object, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(scratch, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
+    movq(smi_index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
   }
 }