py: Treat -m32 flag as part of CC, LD, etc.

Indeed, this flag efectively selects architecture target, and must
consistently apply to all compiles and links, including 3rd-party
libraries, unlike CFLAGS, which have MicroPython-specific setting.

py/mkenv.mk

@@ -46,10 +46,16 @@ PYTHON = python
 
 AS = $(CROSS_COMPILE)as
 CC = $(CROSS_COMPILE)gcc
+CXX = $(CROSS_COMPILE)g++
 LD = $(CROSS_COMPILE)ld
 OBJCOPY = $(CROSS_COMPILE)objcopy
 SIZE = $(CROSS_COMPILE)size
 STRIP = $(CROSS_COMPILE)strip
+ifeq ($(MICROPY_FORCE_32BIT),1)
+CC += -m32
+CXX += -m32
+LD += -m32
+endif
 
 all:
 .PHONY: all

unix/Makefile

@@ -47,8 +47,6 @@ LDFLAGS = $(LDFLAGS_MOD) $(LDFLAGS_ARCH) -lm $(LDFLAGS_EXTRA)
 ifeq ($(MICROPY_FORCE_32BIT),1)
 # Note: you may need to install i386 versions of dependency packages,
 # starting with linux-libc-dev:i386
-CFLAGS += -m32
-LDFLAGS += -m32
 ifeq ($(MICROPY_PY_FFI),1)
 ifeq ($(UNAME_S),Linux)
 CFLAGS_MOD += -I/usr/include/i686-linux-gnu