Subzero: Clean up some uses of *_cast<>.

src/PNaClTranslator.cpp

Index: src/PNaClTranslator.cpp
diff --git a/src/PNaClTranslator.cpp b/src/PNaClTranslator.cpp
index ed2a90785c51d5a6a673b2f91c9f837639053bf9..ed19f61ccfd5b869ecceec984fd3c7785b07c25a 100644
--- a/src/PNaClTranslator.cpp
+++ b/src/PNaClTranslator.cpp
@@ -2737,7 +2737,7 @@ void FunctionParser::ProcessRecord() {
       appendErrorInstruction(ReturnType);
       return;
     }
-    bool IsTailCall = static_cast<bool>(CCInfo & 1);
+    const bool IsTailCall = (CCInfo & 1);
 
     // Create the call instruction.
     Ice::Variable *Dest = (ReturnType == Ice::IceType_void)