Use newly built crt*.o files to build shared objects [BZ #22362]

When multi-lib GCC is used to build glibc, the search order of GCC driver
for crt*.o is -B*/`gcc -print-multi-directory`, the installed diretory,
-B*/.  This patch adds multi-lib support to csu/Makefile so that
-B/glibc-build-directory/csu/ will pick up the newly built crt*.o.

Tested on x86-64 for i686 and x32.

	[BZ #22362]
	* Makerules (make-link-multidir): New.
	* config.make.in (multidir): New.
	* configure.ac (libc_cv_multidir): New.  AC_SUBST.
	* configure: Regenerated.
	* csu/Makefile [$(multidir) != .](multilib-extra-objs): New.
	[$(multidir) != .](extra-objs): Add $(multilib-extra-objs).
	[$(multidir) != .]($(addprefix $(objpfx)$(multidir)/, $(install-lib))):
	New target.

1 files changed, 9 insertions, 0 deletions

diff --git a/Makerules b/Makerules
index bbfbefe33f..522de25cfd 100644
--- a/Makerules
+++ b/Makerules
@@ -1079,6 +1079,11 @@ rm -f $@.new
 $(SHELL) $(..)scripts/rellns-sh $< $@.new
 mv -f $@.new $@
 endef
+define make-link-multidir
+$(patsubst %/,cd %,$(objpfx)); \
+  $(LN_S) . $(multidir) 2> /dev/null; \
+  test -L $(multidir)
+endef
 else
 # If we have no symbolic links don't bother with rellns-sh.
 define make-link
@@ -1086,6 +1091,10 @@ rm -f $@.new
 $(LN_S) $< $@.new
 mv -f $@.new $@
 endef
+define make-link-multidir
+$(make-target-directory)
+ln -f $(objpfx)/$(@F) $@
+endef
 endif
 
 ifeq (yes,$(build-shared))