Merge pull request gridcoin-community#2560 from barton2526/cross

build: Fix x86_64 <-> arm64 cross-compiling for macOS

Author: jamescowens

depends/builders/darwin.mk

@@ -20,3 +20,8 @@ darwin_OTOOL:=$(shell xcrun -f otool)
 darwin_NM:=$(shell xcrun -f nm)
 darwin_INSTALL_NAME_TOOL:=$(shell xcrun -f install_name_tool)
 darwin_native_toolchain=
+
+x86_64_darwin_CFLAGS += -arch x86_64
+x86_64_darwin_CXXFLAGS += -arch x86_64
+aarch64_darwin_CFLAGS += -arch arm64
+aarch64_darwin_CXXFLAGS += -arch arm64