feature.pl: Make the perl.h search more resilient

In case #define is changed to # define some day.  (Not likely, but
this will make things easier for future maintainers.)

diff --git a/regen/feature.pl b/regen/feature.pl
index 3badc70..d862b7c 100755 (executable)
--- a/regen/feature.pl
+++ b/regen/feature.pl
@@ -88,7 +88,7 @@ my $HintMask;
 open "perl.h", "perl.h" or die "$0 cannot open perl.h: $!";
 perlh: {
     while (readline "perl.h") {
-       next unless /#define\s+HINT_FEATURE_MASK/;
+       next unless /#\s*define\s+HINT_FEATURE_MASK/;
        /(0x[A-Fa-f0-9]+)/ or die "No hex number in:\n\n$_\n ";
        my $hex = $HintMask = $1;
        my $bits = sprintf "%b", oct $1;