Move some compiler intrinsic #defines to base/.

base/compiler_specific.h

Index: base/compiler_specific.h
diff --git a/base/compiler_specific.h b/base/compiler_specific.h
index 0dbc3ae576688908b41a1b5921c744a71f5ada4c..bb4c52be45e298b31c73566f8b927445a7a952f4 100644
--- a/base/compiler_specific.h
+++ b/base/compiler_specific.h
@@ -100,6 +100,14 @@
 #define NOINLINE
 #endif
 
+#if COMPILER_GCC && defined(NDEBUG)
+#define ALWAYS_INLINE inline __attribute__((__always_inline__))
+#elif COMPILER_MSVC && defined(NDEBUG)
+#define ALWAYS_INLINE __forceinline
+#else
+#define ALWAYS_INLINE inline
+#endif
+
 // Specify memory alignment for structs, classes, etc.
 // Use like:
 //   class ALIGNAS(16) MyClass { ... }
@@ -196,6 +204,14 @@
 #endif  // defined(COMPILER_GCC)
 #endif  // !defined(UNLIKELY)
 
+#if !defined(LIKELY)
+#if defined(COMPILER_GCC)
+#define LIKELY(x) __builtin_expect((x), 1)

[sdefresne, 2016/11/08 08:40:20]

Shouldn't this be __builtin_expect(!!(x), 1)? Otherwise, the following will be
fails the LIKELY:

Foo* ptr = new Foo;
if (LIKELY(ptr)) {
  ...
}

[palmer, 2016/11/16 23:45:21]

Somehow, I missed this comment. Fix coming right up. Thanks!

+#else
+#define LIKELY(x) (x)
+#endif  // defined(COMPILER_GCC)
+#endif  // !defined(LIKELY)
+
 // Compiler feature-detection.
 // clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension
 #if defined(__has_feature)