devel/freebsd-gcc12: Use -stdlib=libc++ to use libc++.

Instead of overriding the path and library name of libstdc++, set the
path for libc++ and change the default of -stdlib= from libstdc++ to
libc++.

devel/freebsd-gcc12/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	gcc
 PORTVERSION=	12.2.0
-PORTREVISION=	8
+PORTREVISION=	9
 CATEGORIES=	devel
 MASTER_SITES=	GCC
 PKGNAMEPREFIX=	${TARGETARCH}-
@@ -53,7 +53,7 @@ CONFIGURE_ARGS+=--target=${GCC_TARGET} --disable-nls --enable-languages=c,c++ \
 		--with-pkgversion="FreeBSD Ports Collection for ${PKGNAMEPREFIX:C/-//g}" \
 		--with-system-zlib \
 		--without-zstd \
-		--with-gxx-include-dir=/usr/include/c++/v1/ \
+		--with-gxx-libcxx-include-dir=//usr/include/c++/v1 \
 		--with-sysroot="/" \
 		--with-as=${LOCALBASE}/bin/${BU_PREFIX}-as \
 		--with-ld=${LOCALBASE}/bin/${BU_PREFIX}-ld
@@ -62,6 +62,8 @@ CONFIGURE_ARGS+=--target=${GCC_TARGET} --disable-nls --enable-languages=c,c++ \
 CONFIGURE_ARGS+=--with-abi=elfv2
 .endif
 
+CPPFLAGS+=	-DLIBCXXABI=NULL
+
 ALL_TARGET=	all-gcc
 INSTALL_TARGET=	install-gcc
 
@@ -79,8 +81,6 @@ BU_PREFIX=	${GCC_TARGET}
 GCC_TARGET=	${TARGETARCH:S/amd64/x86_64/}-${TARGET_ABI}-${OPSYS:tl}${OSREL}
 
 post-patch:
-	@${REINPLACE_CMD} -e '/LIBSTDCXX/ s/stdc\+\+/c\+\+/g ' \
-		${WRKSRC}//gcc/cp/g++spec.cc
 	@${REINPLACE_CMD} -e '/LOCAL_INCLUDE_DIR/ d ' \
 		${WRKSRC}//gcc/Makefile.in
 

devel/freebsd-gcc12/files/patch-gcc_c-family_c.opt

@@ -0,0 +1,11 @@
+--- gcc/c-family/c.opt.orig	2023-07-01 21:56:03 UTC
++++ gcc/c-family/c.opt
+@@ -2464,7 +2464,7 @@ stdlib=
+ Conform to the ISO 2017 C standard (published in 2018).
+
+ stdlib=
+-Driver C++ ObjC++ Common Condition(ENABLE_STDLIB_OPTION) Var(flag_stdlib_kind) Joined Enum(stdlib_kind) RejectNegative Init(1)
++Driver C++ ObjC++ Common Condition(ENABLE_STDLIB_OPTION) Var(flag_stdlib_kind) Joined Enum(stdlib_kind) RejectNegative Init(2)
+ -stdlib=[libstdc++|libc++]	The standard library to be used for C++ headers
+ and runtime.
+

devel/freebsd-gcc12/files/patch-gcc_cp_g++spec.cc

@@ -0,0 +1,11 @@
+--- gcc/cp/g++spec.cc.orig	2023-05-08 12:14:39 UTC
++++ gcc/cp/g++spec.cc
+@@ -95,7 +95,7 @@ lang_specific_driver (struct cl_decoded_option **in_de
+   int library = 0;
+
+   /* Which c++ runtime library to link.  */
+-  stdcxxlib_kind which_library = USE_LIBSTDCXX;
++  stdcxxlib_kind which_library = USE_LIBCXX;
+
+   /* The number of arguments being added to what's in argv, other than
+      libraries.  We use this to track the number of times we've inserted