Always provide a librdkafka-static.a

Even if there are no dependency .a to bundle we should still provide a librdkafka-static.a, since it
may be sufficient anyway.

This change originally stems from the RPM package librdkafka.spec including librdkafka-static.a, but
depending on Redhat distro it may or may not need static library dependencies, which in turn would
sometime not create a librdkafka-static.a, thus failing RPM packaging.

mklove/Makefile.base

@@ -162,8 +162,14 @@ endif # MKL_DYNAMIC_LIBS
 
 else # MKL_STATIC_LIBS is empty
 _STATIC_FILENAME=$(LIBNAME).a
-$(LIBNAME)-static.a:
-	@printf "$(MKL_RED)WARNING:$(MKL_YELLOW) $@: Not creating self-contained static library $@: no static libraries available/enabled$(MKL_CLR_RESET)\n"
+$(LIBNAME)-static.a: $(LIBNAME).a
+	@printf "$(MKL_RED)WARNING:$(MKL_YELLOW) $@: No static libraries available/enabled for inclusion in self-contained static library $@: this library will be identical to $(LIBNAME).a$(MKL_CLR_RESET)\n"
+ifneq ($(MKL_DYNAMIC_LIBS),)
+	@printf "$(MKL_RED)WARNING:$(MKL_YELLOW) $@: The following libraries were not available as static libraries and need to be linked dynamically: $(MKL_DYNAMIC_LIBS)$(MKL_CLR_RESET)\n"
+	cp $(LIBNAME).a $@
+	cp $(LIBNAME)-dbg.a $(LIBNAME)-static-dbg.a
+	cp $@ $(LIBNAME)-static-dbg.a
+endif # MKL_DYNAMIC_LIBS
 endif # MKL_STATIC_LIBS
 
 endif # MKL_NO_SELFCONTAINED_STATIC_LIB