Bug#42733: Type-punning warnings when compiling MySQL --

           strict aliasing violations.

Post-merge fix: include my_compiler.h before my_attribute.h
as the latter will undef __attribute__ if the compiler is not
GCC. Based on the compiler version, in my_compiler.h we know
for sure whether the aligned attribute is supported. Furthermore,
undefining attribute might cause bugs if some system header
uses it.

include/my_compiler.h:
  Drop aligned attribute support from Sun Studio C++ compiler
  as its not clear exactly which version of it supports the
  attribute.

include/my_compiler.h

@@ -42,7 +42,7 @@
 
 /* Oracle Solaris Studio */
 #elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
-# if (__SUNPRO_C >= 0x590) || (__SUNPRO_CC >= 0x590)
+# if __SUNPRO_C >= 0x590
 #   define MY_ALIGN_EXT
 # endif
 
@@ -124,4 +124,6 @@ struct my_aligned_storage
 
 #endif /* __cplusplus */
 
+#include <my_attribute.h>
+
 #endif /* MY_COMPILER_INCLUDED */

include/my_global.h

@@ -623,7 +623,7 @@ typedef unsigned short ushort;
 #define my_const_cast(A) (A)
 #endif
 
-#include <my_attribute.h>
+#include <my_compiler.h>
 
 /*
   Wen using the embedded library, users might run into link problems,

sql/spatial.h

@@ -16,8 +16,6 @@
 #ifndef _spatial_h
 #define _spatial_h
 
-#include <my_compiler.h>
-
 #ifdef HAVE_SPATIAL
 
 const uint SRID_SIZE= 4;