regen/embed.pl: Handle m with p flags

Prior to this commit these were illegal.  This allows it when there is
no pesky thread context in the way.

This causes embed.fnc to generate macro 'Perl_foo' #defined to be  macro
'foo'.  This could be used to easily convert existing macros into having
long names should that become a name space pollution problem.

But more immediately, we have scattered around, various one line
functions that simply call something else.  Those were typically created
to preserve the pre-existing API should someone be using the long name,
and the implementation changed.

This commit allows those (that don't use thread context) to be
conveniently replaced by a macro.  The next couple commits will do that
for a couple of them.

Author: khwilliamson

autodoc.pl

@@ -1899,7 +1899,7 @@ ($fh, $section_name, $element_name, $docref)
                     # Here, has a long name and we didn't create one just
                     # above.  Check that there really is a long name entry.
                     my $real_proto = delete $protos{"Perl_$name"};
-                    if ($real_proto) {
+                    if ($real_proto || $flags =~ /m/) {
 
                         # Set up to redo the loop at the end.  This iteration
                         # adds the short form; the redo causes its long form

regen/embed.pl

@@ -137,11 +137,18 @@ sub generate_proto_h {
 
         die_at_end "$plain_func: S and p flags are mutually exclusive"
                                             if $flags =~ /S/ && $flags =~ /p/;
-        die_at_end "$plain_func: m and $1 flags are mutually exclusive"
-                                        if $has_mflag && $flags =~ /([pS])/;
-
-        die_at_end "$plain_func: u flag only usable with m" if $flags =~ /u/
-                                                            && ! $has_mflag;
+	if ($has_mflag) {
+	    if ($flags =~ /S/) {
+		die_at_end "$plain_func: m and S flags are mutually exclusive";
+	    }
+	    elsif ($flags =~ /p/ && $has_context) {
+		die_at_end "$plain_func: m flag with p flag currently requires"
+		         . " T flag";
+	    }
+	}
+	else {
+	    die_at_end "$plain_func: u flag only usable with m" if $flags =~ /u/;
+	}
 
         my ($static_flag, @extra_static_flags)= $flags =~/([SsIi])/g;
 
@@ -500,9 +507,9 @@ sub embed_h {
         my $ind= $level ? " " : "";
         $ind .= "  " x ($level-1) if $level>1;
         my $inner_ind= $ind ? "  " : " ";
-        unless ($flags =~ /[omM]/) {
+        if ($flags !~ /[omM]/ or ($flags =~ /m/ && $flags =~ /p/)) {
             my $argc = scalar @$args;
-            if ($flags =~ /T/) {
+            if ($flags =~ /[Tm]/) {
                 my $full_name = full_name($func, $flags);
                 next if $full_name eq $func;    # Don't output a no-op.
                 $ret = indent_define($func, $full_name, $ind);