utf8.c: Faster latin1 folding

This adds a function similar to the ones for the other three case
changing operations that works on latin1 characters only, and avoids
having to go out to swashes.  It changes to_uni_fold() and
to_utf8_fold() to call it on the appropriate input

1 files changed, 6 insertions, 0 deletions

diff --git a/proto.h b/proto.h
index 7f9621a47e..534fab8511 100644
--- a/proto.h
+++ b/proto.h
@@ -6983,6 +6983,12 @@ STATIC bool	S_isa_lookup(pTHX_ HV *stash, const char * const name, STRLEN len, U
 
 #endif
 #if defined(PERL_IN_UTF8_C)
+PERL_CALLCONV UV	Perl__to_fold_latin1(pTHX_ const U8 c, U8 *p, STRLEN *lenp, const U8 flags)
+			__attribute__nonnull__(pTHX_2)
+			__attribute__nonnull__(pTHX_3);
+#define PERL_ARGS_ASSERT__TO_FOLD_LATIN1	\
+	assert(p); assert(lenp)
+
 PERL_CALLCONV UV	Perl__to_upper_title_latin1(pTHX_ const U8 c, U8 *p, STRLEN *lenp, const char S_or_s)
 			__attribute__nonnull__(pTHX_2)
 			__attribute__nonnull__(pTHX_3);