MDEV-19709 Workaround "internal compiler bug" on GCC v 4.9

GCC crashes during compilation, on a code fragment that was added  to
workaround code generation bug on GCC.

To fix, I randomly moved pragmas around, which seems to make GCC happy.

sql/sql_bitmap.h

@@ -27,6 +27,10 @@
 #include <my_bitmap.h>
 #include <my_bit.h>
 
+
+template <uint width> class Bitmap
+{
+
 /*
   Workaround GCC optimizer bug (generating SSE instuctions on unaligned data)
 */
@@ -39,8 +43,6 @@
 #pragma GCC target ("no-sse")
 #endif
 
-template <uint width> class Bitmap
-{
   uint32 buffer[(width + 31) / 32];
 public:
   Bitmap()
@@ -276,13 +278,15 @@ public:
     }
     enum { BITMAP_END = width };
   };
-};
 
 #ifdef NEED_GCC_NO_SSE_WORKAROUND
 #pragma GCC pop_options
 #undef NEED_GCC_NO_SSE_WORKAROUND
 #endif
 
+};
+
+
 /* An iterator to quickly walk over bits in ulonglong bitmap. */
 class Table_map_iterator
 {