Use BLDLIBRARY as single source of truth for flags within Python's own build process

Author: mhsmith

Makefile.pre.in

@@ -44,7 +44,6 @@ ABIFLAGS=	@ABIFLAGS@
 ABI_THREAD=	@ABI_THREAD@
 LDVERSION=	@LDVERSION@
 LIBPYTHON=@LIBPYTHON@
-MODULE_LDFLAGS_SHARED=$(if $(LIBPYTHON),-L. $(LIBPYTHON))
 GITVERSION=	@GITVERSION@
 GITTAG=		@GITTAG@
 GITBRANCH=	@GITBRANCH@
@@ -286,6 +285,7 @@ DIST=		$(DISTFILES) $(DISTDIRS)
 LIBRARY=	@LIBRARY@
 LDLIBRARY=      @LDLIBRARY@
 BLDLIBRARY=     @BLDLIBRARY@
+MODULE_LDFLAGS_SHARED=$(if $(LIBPYTHON),$(BLDLIBRARY))
 PY3LIBRARY=     @PY3LIBRARY@
 DLLLIBRARY=	@DLLLIBRARY@
 LDLIBRARYDIR=   @LDLIBRARYDIR@