utf8.h: Refactor UNICODE_IS_NONCHAR()

This adds branch prediction and re-orders so that an unlikely to succeed
test is done before the likely to succeed one, so that the latter
usually doesn't need to be executed.  Since both conditions must succeed
for the entire expression to succeed, this doesn't change what the whole
expresson matches.

s# Please enter the commit message for your changes. Lines starting

utf8.h

@@ -970,9 +970,9 @@ Evaluates to 0xFFFD, the code point of the Unicode REPLACEMENT CHARACTER
                                       UNLIKELY(((UV) (uv) & 0xFFFE) == 0xFFFE)
 
 #define UNICODE_IS_NONCHAR(uv)                                                  \
-    (   UNICODE_IS_32_CONTIGUOUS_NONCHARS(uv)                                   \
-     || (   LIKELY( ! UNICODE_IS_SUPER(uv))                                     \
-         && UNICODE_IS_END_PLANE_NONCHAR_GIVEN_NOT_SUPER(uv)))
+    (       UNLIKELY(UNICODE_IS_32_CONTIGUOUS_NONCHARS(uv))                     \
+     || (   UNLIKELY(UNICODE_IS_END_PLANE_NONCHAR_GIVEN_NOT_SUPER(uv))          \
+         && LIKELY(! UNICODE_IS_SUPER(uv))))
 
 #define UNICODE_IS_SUPER(uv)    UNLIKELY((UV) (uv) > PERL_UNICODE_MAX)