Merge pull request #3 from xamarin/dev/lluis/libpty-as-fat-lib

Build libtpy as a fat library

helper/Makefile

@@ -1,8 +1,17 @@
 all: libtpy.dylib
 
-libpty.dylib: pty.c
-	cc -shared pty.c -shared -o libpty.dylib
+ifeq ($(OS),Windows_NT)
+    UNAME := Windows
+else
+    UNAME := $(shell uname -s)
+endif
 
+libpty.dylib: pty.c
+	@if [[ "$(UNAME)" == "Darwin" ]]; then \
+		cc -arch arm64 -arch x86_64 -shared pty.c -shared -o libpty.dylib; \
+	else \
+		cc -shared pty.c -shared -o libpty.dylib; \
+	fi
 
 clean:
 	rm *dylib