locale.c: Move #define to perl.h; use it elsewhere

 Rather than recalculate this combined conditional, do it once in
 perl.h.

intrpvar.h

@@ -717,9 +717,7 @@ PERLVAR(I, constpadix,	PADOFFSET)	/* lowest unused for constants */
 
 PERLVAR(I, padix_floor,	PADOFFSET)	/* how low may inner block reset padix */
 
-#if defined(USE_POSIX_2008_LOCALE)          \
- && defined(USE_THREAD_SAFE_LOCALE)         \
- && ! defined(HAS_QUERYLOCALE)
+#ifdef USE_PL_CURLOCALES
 
 /* This is the most number of categories we've encountered so far on any
  * platform */

locale.c

@@ -571,9 +571,7 @@ Perl_locale_panic(const char * msg,
 #  define querylocale_c(cat)    querylocale_i(cat##_INDEX_)
 #  define querylocale_r(cat)    querylocale_i(get_category_index(cat,NULL))
 
-#  ifndef USE_QUERYLOCALE
-#    define USE_PL_CURLOCALES
-#  else
+#  ifdef USE_QUERYLOCALE
 #    define isSINGLE_BIT_SET(mask) isPOWER_OF_2(mask)
 
      /* This code used to think querylocale() was valid on LC_ALL.  Make sure

makedef.pl

@@ -159,6 +159,12 @@ BEGIN
     $define{USE_POSIX_2008_LOCALE} = 1 if $define{HAS_POSIX_2008_LOCALE};
 }
 
+if (   ($define{USE_POSIX_2008_LOCALE} && ! $define{HAS_QUERYLOCALE})
+    || ($define{USE_LOCALE_THREADS} && ! $define{USE_THREAD_SAFE_LOCALE}))
+{
+    $define{USE_PL_CURLOCALES} = 1;
+}
+
 if (   $ARGS{PLATFORM} eq 'win32'
     && $define{USE_THREAD_SAFE_LOCALE}
     && $cctype < 140)
@@ -417,7 +423,7 @@ sub readvar {
         PL_underlying_numeric_obj
     );
 }
-unless ($define{USE_POSIX_2008_LOCALE} && ! $define{HAS_QUERY_LOCALE})
+unless ($define{USE_PL_CURLOCALES})
 {
     ++$skip{$_} foreach qw(
         PL_curlocales

perl.c

@@ -1109,9 +1109,7 @@ perl_destruct(pTHXx)
     Safefree(PL_collation_name);
     PL_collation_name = NULL;
 #endif
-#if   defined(USE_POSIX_2008_LOCALE)      \
- &&   defined(USE_THREAD_SAFE_LOCALE)     \
- && ! defined(HAS_QUERYLOCALE)
+#if defined(USE_PL_CURLOCALES)
     for (i = 0; i < (int) C_ARRAY_LENGTH(PL_curlocales); i++) {
         Safefree(PL_curlocales[i]);
         PL_curlocales[i] = NULL;

perl.h

@@ -1118,6 +1118,11 @@ Example usage:
 #    endif
 #  endif
 
+#  if (defined(USE_POSIX_2008_LOCALE) && ! defined(USE_QUERYLOCALE))        \
+   || (defined(USE_LOCALE_THREADS) && ! defined(USE_THREAD_SAFE_LOCALE))
+#    define USE_PL_CURLOCALES
+#  endif
+
 /*  Microsoft documentation reads in the change log for VS 2015:
  *     "The localeconv function declared in locale.h now works correctly when
  *     per-thread locale is enabled. In previous versions of the library, this

sv.c

@@ -15645,9 +15645,7 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
 
     PL_subname		= sv_dup_inc(proto_perl->Isubname, param);
 
-#if   defined(USE_POSIX_2008_LOCALE)      \
- &&   defined(USE_THREAD_SAFE_LOCALE)     \
- && ! defined(HAS_QUERYLOCALE)
+#ifdef USE_PL_CURLOCALES
     for (i = 0; i < (int) C_ARRAY_LENGTH(PL_curlocales); i++) {
         PL_curlocales[i] = SAVEPV(proto_perl->Icurlocales[i]);
     }