$NetBSD$

Support Darwin/aarch64, from https://github.com/Homebrew/formula-patches.

--- /dev/null
+++ libgcc/config/aarch64/t-darwin
@@ -0,0 +1,7 @@
+# Ensure we have a suitable minimum OS version.
+
+HOST_LIBGCC2_CFLAGS += -mmacosx-version-min=11.0
+
+LIB2_SIDITI_CONV_FUNCS = yes
+
+BUILD_LIBGCCS1 =