x86/emul: Fix test harness build with blk.c moved out of x86_emulate.c

Trying to build the test harness fails with:

  x86_emulate/blk.c: In function 'x86_emul_blk':
  x86_emulate/blk.c:74:15: error: expected ':' or ')' before 'ASM_FLAG_OUT'
     74 |               ASM_FLAG_OUT(, "; setz %[zf]")
        |               ^~~~~~~~~~~~

This is because ASM_FLAG_OUT() is still local to x86_emulate.c.  Move it into
x86-emulate.h instead so it ends up in all files including private.h.  The
main Xen build gets this macro from compiler.h.

Fixes: c80243f943 ("x86emul: move x86_emul_blk() to separate source file")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

tools/tests/x86_emulator/x86-emulate.h

@@ -65,6 +65,12 @@
 #define AC_(n,t) (n##t)
 #define _AC(n,t) AC_(n,t)
 
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+# define ASM_FLAG_OUT(yes, no) yes
+#else
+# define ASM_FLAG_OUT(yes, no) no
+#endif
+
 #define hweight32 __builtin_popcount
 #define hweight64 __builtin_popcountll
 

xen/arch/x86/x86_emulate/x86_emulate.c

@@ -132,12 +132,6 @@ static const uint8_t sse_prefix[] = { 0x66, 0xf3, 0xf2 };
         (void *)(((long)__##var + __alignof(type) - __alignof(__##var))   \
                  & -__alignof(type))
 
-#ifdef __GCC_ASM_FLAG_OUTPUTS__
-# define ASM_FLAG_OUT(yes, no) yes
-#else
-# define ASM_FLAG_OUT(yes, no) no
-#endif
-
 /* MXCSR bit definitions. */
 #define MXCSR_MM  (1U << 17)