Forcibly inline bit_cast when building with GCC.

src/base/macros.h

Index: src/base/macros.h
diff --git a/src/base/macros.h b/src/base/macros.h
index 7a3561878b6debcdfb248370d2ef48b3eef62938..cef088cb8194497eb0a86dfee1720c981a666bd6 100644
--- a/src/base/macros.h
+++ b/src/base/macros.h
@@ -230,7 +230,7 @@ struct CompileAssert {};
 // WARNING: if Dest or Source is a non-POD type, the result of the memcpy
 // is likely to surprise you.
 template <class Dest, class Source>
-inline Dest bit_cast(const Source& source) {
+V8_INLINE Dest bit_cast(Source const& source) {
   COMPILE_ASSERT(sizeof(Dest) == sizeof(Source), VerifySizesAreEqual);
 
   Dest dest;