PATCH: GH #17370, read beyond buffer in grok_inf_nan

Like GH #17367, this was caused by a failure to check that we aren't at
the end of the buffer after advancing the ptr to it.

t/re/pat.t

@@ -24,7 +24,7 @@ BEGIN {
 
 skip_all_without_unicode_tables();
 
-plan tests => 1012;  # Update this when adding/deleting tests.
+plan tests => 1013;  # Update this when adding/deleting tests.
 
 run_tests() unless caller;
 
@@ -2084,6 +2084,9 @@ CODE
     {   # [perl #133871], ASAN/valgrind out-of-bounds access
         fresh_perl_like('qr/\p{nv:NAnq}/', qr/Can't find Unicode property definition/, {}, "GH #17367");
     }
+    {   # GH #17370, ASAN/valgrind out-of-bounds access
+        fresh_perl_like('qr/\p{nv:qnan}/', qr/Can't find Unicode property definition/, {}, "GH #17370");
+    }
 
   SKIP:
     {   # [perl #133921], segfault