Fix lang/gcc46 cross-build on NetBSD.  XXX unfinished, no worky yet

Index: lang/gcc46/Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/lang/gcc46/Makefile,v
retrieving revision 1.22
diff -p -u -r1.22 Makefile
--- lang/gcc46/Makefile	3 Oct 2012 21:56:18 -0000	1.22
+++ lang/gcc46/Makefile	23 Apr 2013 13:29:18 -0000
@@ -12,7 +12,7 @@ HOMEPAGE=		http://gcc.gnu.org/
 COMMENT=		GNU Compiler Collection 4.6
 LICENSE=		gnu-gpl-v2 AND gnu-gpl-v3 AND gnu-lgpl-v2 AND gnu-lgpl-v3
 
-USE_TOOLS+=		awk:run bash:run chmod gmake:run makeinfo sed:run
+USE_TOOLS+=		awk:run bash chmod gmake:run makeinfo sed:run
 
 GCC_VERSION=		4.6.3
 
@@ -64,6 +64,28 @@ REPLACE_BASH+= gcc/dbgcnt.def
 REPLACE_BASH+= gcc/testsuite/gcc.test-framework/gen_directive_tests
 REPLACE_BASH+= libstdc++-v3/scripts/run_doxygen
 
+# This is necessary because we don't set GNU_CONFIGURE (XXX why not?).
+CONFIGURE_ARGS+=	--build=${NATIVE_MACHINE_GNU_PLATFORM:Q}
+CONFIGURE_ARGS+=	--host=${MACHINE_GNU_PLATFORM:Q}
+
+.if !empty(USE_CROSS_COMPILE:M[yY][eE][sS])
+CONFIGURE_ENV+=		CC_FOR_BUILD=${NATIVE_CC:Q}
+CONFIGURE_ENV+=		CXX_FOR_BUILD=${NATIVE_CXX:Q}
+
+SUBST_CLASSES+=		gccinc
+SUBST_FILES.gccinc+=	libgcc/Makefile.in
+SUBST_MESSAGE.gccinc=	Add -I$$(gcc_objdir)/include to INCLUDES in libgcc.
+SUBST_STAGE.gccinc=	pre-configure
+SUBST_SED.gccinc+=	\
+	-e 's,^INCLUDES = .* -I$$(gcc_objdir) ,&-I$$(gcc_objdir)/include ,1'
+.endif
+
+SUBST_CLASSES+=		subhack
+SUBST_FILES.subhack+=	gcc/Makefile.in
+SUBST_MESSAGE.subhack=	Mega-kludgerosity for GCC SHLIB_LINK substibustication!
+SUBST_STAGE.subhack=	pre-configure
+SUBST_SED.subhack+=	\
+	-e 's:subst $$(GCC_FOR_TARGET),$$$$(GCC_FOR_TARGET),:subst $$(GCC_FOR_TARGET) $$(LIBGCC2_FLAGS),$$$$(GCC_FOR_TARGET) $$(LIBGCC2_FLAGS),:1'
 
 CONFIGURE_ARGS+=	--prefix=${GCC_PREFIX:Q}
 CONFIGURE_ARGS+=	--enable-languages=${LANGS:Q}