Tool for snipping loader_commands in Mach-O on Apple M1 (aarch64) on BigSur.

experimental!
https://github.com/upx/upx/issues/424
	new file:   macho-snip/Makefile
	new file:   macho-snip/macho-snip.c
	new file:   macho-snip/udf.s

src/stub/tools/macho-snip/Makefile

@@ -0,0 +1,21 @@
+# Required: Apple Command Line Developer Tools: "xcode-select --install"
+#    Downloads a few megabytes.  Installs in a couple minutes.
+# Required: Apple Xcode Developer Tools from Apple App Store.
+#    Must accept the license:  Launch Xcode app,
+#    or run "xcodebuild -license" from Terminal after install.
+#    Downloads about 13GB (~20 minutes at 1Gb/s).  Install takes
+#    ~45 minutes more on SSD, and ~40GB of space in the filesystem.
+
+CFLAGS += -g
+
+macho-snip: macho-snip.o udf
+	$(CC) $(CFLAGS) -o macho-snip macho-snip.o
+
+udf.o: udf.s
+	gcc -c $<
+
+# shortest main program;  used as an example
+udf: udf.o
+	gcc --verbose -nostartfiles -o udf $<
+	codesign --remove-signature udf
+	strip -N udf  # removes all symbols