ck_cc: Add CK_CC_ALIASED attribute.

Submitted by John Wittrock <jwittrock@...>.

include/ck_cc.h

@@ -45,4 +45,8 @@
 
 #define CK_CC_PAD(x) union { char pad[x]; }
 
+#ifndef CK_CC_ALIASED
+#define CK_CC_ALIASED
+#endif
+
 #endif /* _CK_CC_H */

include/gcc/ck_cc.h

@@ -75,4 +75,11 @@
 #pragma GCC poison malloc free
 #endif
 
+/*
+ * Some compilers are overly strict regarding aliasing semantics.
+ * Unfortunately, in many cases it makes more sense to pay aliasing
+ * cost rather than overly expensive register spillage.
+ */
+#define CK_CC_ALIASED __attribute__((__may_alias__))
+
 #endif /* _CK_GCC_CC_H */