Add DUK_HOT and DUK_COLD attribute macros

config/compilers/compiler_clang.h.in

@@ -29,6 +29,9 @@
 #define DUK_ALWAYS_INLINE   inline __attribute__((always_inline))
 #endif
 
+/* DUK_HOT */
+/* DUK_COLD */
+
 #if defined(DUK_F_DLL_BUILD) && defined(DUK_F_WINDOWS)
 #snippet "msvc_visibility.h.in"
 #else

config/compilers/compiler_gcc.h.in

@@ -33,6 +33,12 @@
 #define DUK_ALWAYS_INLINE   inline __attribute__((always_inline))
 #endif
 
+#if (defined(DUK_F_C99) || defined(DUK_F_CPP11)) && \
+    defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION >= 40300)
+#define DUK_HOT             __attribute__((hot))
+#define DUK_COLD            __attribute__((cold))
+#endif
+
 #if defined(DUK_F_DLL_BUILD) && defined(DUK_F_WINDOWS)
 #snippet "msvc_visibility.h.in"
 #elif defined(DUK_F_GCC_VERSION) && (DUK_F_GCC_VERSION >= 40000)

config/header-snippets/compiler_fillins.h.in

@@ -80,6 +80,13 @@
 #define DUK_ALWAYS_INLINE  /*nop*/
 #endif
 
+#if !defined(DUK_HOT)
+#define DUK_HOT            /*nop*/
+#endif
+#if !defined(DUK_COLD)
+#define DUK_COLD           /*nop*/
+#endif
+
 #if !defined(DUK_EXTERNAL_DECL)
 #define DUK_EXTERNAL_DECL  extern
 #endif