Add lock_definitions.h

This file is intended to insulate C code from thread issues, when used
as directed.

MANIFEST

@@ -61,6 +61,7 @@ keywords.h				The keyword numbers
 l1_char_class_tab.h			256 word bit table of character classes (for handy.h)
 locale.c				locale-specific utility functions
 locale_table.h				header for locale.c
+lock_definitions.h
 make_ext.pl				Used by Makefile to execute extension Makefiles
 make_patchnum.pl			Script to generate git_version.h and lib/Config_git.pl files for all OS'es
 makedef.pl				Create symbol export lists for linking
@@ -5921,6 +5922,7 @@ regen/HeaderParser.pm			Module used to parse header files
 regen/keywords.pl			Program to write keywords.h
 regen/lib_cleanup.pl			Generate lib/.gitignore from MANIFEST
 regen/locale.pl				Program to write locale_table.h
+regen/lock_definitions.pl		Program to write lock_definitions.h
 regen/mg_vtable.pl			generate mg_vtable.h
 regen/miniperlmain.pl			generate miniperlmain.c
 regen/mk_invlists.pl			Generates charclass_invlists.h

Makefile.SH

@@ -1263,6 +1263,7 @@ CHMOD_W = chmod +w
 #	warnings.pl:	warnings.h lib/warnings.pm
 #	feature.pl:	feature.h lib/feature.pm
 #	locale.pl:	locale_table.h
+#	lock_definitions.pl: lock_definitions.h
 # The correct versions should be already supplied with the perl kit,
 # in case you don't have perl available.
 # To force them to be regenerated, run