build: add rust target for macOS cross compiles

When we build the macOS pkg, we build Node.js twice (on arm64):
- Once for arm64 (native)
- Once for x64, using a combination of Rosetta 2 and compiler flags

before combining both into a universal binary.

For the x64 case, pass target flag to `rustc` so that the binary is
built for the correct target architecture.

Signed-off-by: Richard Lau <[email protected]>

Author: richardlau

Makefile

@@ -1175,6 +1175,7 @@ endif
 			| sed -E "s/\\{npmversion\\}/$(NPMVERSION)/g"  \
 		>$(MACOSOUTDIR)/installer/productbuild/Resources/$$lang/conclusion.html ; \
 	done
+	RUSTC="rustc --target x86_64-apple-darwin" \
 	CC_host="cc -arch x86_64" CXX_host="c++ -arch x86_64"  \
 	CC_target="cc -arch x86_64" CXX_target="c++ -arch x86_64" \
 	CC="cc -arch x86_64" CXX="c++ -arch x86_64" $(PYTHON) ./configure \