Use toolchain ar instead of declaring it explicitly
https://bugs.gentoo.org/725772
--- a/libjconfig/Makefile.in
+++ b/libjconfig/Makefile.in
@@ -163,7 +163,6 @@
 Makefile: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.in  $(top_builddir)/config.status
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)
 
-AR = ar
 
 clean-noinstLIBRARIES:
 	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)
--- a/librbc/Makefile.in
+++ b/librbc/Makefile.in
@@ -169,7 +169,6 @@
 Makefile: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.in  $(top_builddir)/config.status
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)
 
-AR = ar
 
 clean-noinstLIBRARIES:
 	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)
--- a/libsbp2/Makefile.in
+++ b/libsbp2/Makefile.in
@@ -185,7 +185,6 @@
 Makefile: @MAINTAINER_MODE_TRUE@ $(srcdir)/Makefile.in  $(top_builddir)/config.status
 	cd $(top_builddir) && $(SHELL) ./config.status $(subdir)/$@ $(am__depfiles_maybe)
 
-AR = ar
 
 clean-noinstLIBRARIES:
 	-test -z "$(noinst_LIBRARIES)" || rm -f $(noinst_LIBRARIES)