Stop substr re optimisation from rejecting long strs

Using I32 for the fields that record information about the location of
a fixed string that must be found for a regular expression to match
can result in match failures, because I32 is not large enough to store
offsets >= 2**31.

SSize_t is appropriate, since it is 64 bits on 64-bit platforms and 32
bits on 32-bit platforms.

This commit changes enough instances of I32 to SSize_t to get the
added test passing and suppress compiler warnings.  A later commit
will change many more.

1 files changed, 2 insertions, 2 deletions

diff --git a/regexec.c b/regexec.c
index 29991b5820..eaabe8c896 100644
--- a/regexec.c
+++ b/regexec.c
@@ -615,7 +615,7 @@ Perl_re_intuit_start(pTHX_
 {
     dVAR;
     struct regexp *const prog = ReANY(rx);
-    I32 start_shift = 0;
+    SSize_t start_shift = 0;
     /* Should be nonnegative! */
     I32 end_shift   = 0;
     char *s;
@@ -751,7 +751,7 @@ Perl_re_intuit_start(pTHX_
        the "check" substring in the region corrected by start/end_shift. */
     
     {
-        I32 srch_start_shift = start_shift;
+        SSize_t srch_start_shift = start_shift;
         I32 srch_end_shift = end_shift;
         U8* start_point;
         U8* end_point;