libstdthreads on sparc64/base-gcc archs

The diff below lets libstdthreads build on sparc64. Making this build
with base-gcc look more convoluted. Should this code move to base one
day, we'd probably build it with clang anyway.

FWIW __has_extension has been introduced in gcc >= 14.

ok?


Index: Makefile
===================================================================
RCS file: /cvs/ports/devel/libstdthreads/Makefile,v
diff -u -p -r1.2 Makefile
--- Makefile 21 Sep 2023 09:49:59 -0000 1.2
+++ Makefile 1 Sep 2024 19:50:30 -0000
@@ -13,6 +13,8 @@ SHARED_LIBS += stdthreads
PERMIT_PACKAGE = Yes

WANTLIB = pthread
+COMPILER = base-clang ports-gcc
+COMPILER_LANGS = c

FAKE_FLAGS = LIBDIR=${TRUEPREFIX}/lib \
MANDIR=${TRUEPREFIX}/man/man
Index: patches/patch-threads_h
===================================================================
RCS file: patches/patch-threads_h
diff -N patches/patch-threads_h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-threads_h 1 Sep 2024 19:50:30 -0000
@@ -0,0 +1,16 @@
+__has_extension support added in gcc >= 14
+
+Index: threads.h
+--- threads.h.orig
++++ threads.h
+@@ -45,6 +45,10 @@
+ * held.
+ */
+
++#ifndef __has_extension
++#define __has_extension(_e) 0
++