tcc: re-enable correct option -r support

Forgot about it.  It allows to compile several
sources (and other .o's) to one single .o file;

    tcc -r -o all.o f1.c f2.c f3.S o4.o ...

Also:
- option -fold-struct-init-code removed, no effect anymore
- (tcc_)set_environment() moved to tcc.c
- win32/lib/(win)crt1 minor fix & add dependency
- debug line output for asm (tcc -c -g xxx.S) enabled
- configure/Makefiles: x86-64 -> x86_64 changes
- README: cleanup

tests/Makefile

@@ -36,13 +36,13 @@ endif
 ifeq ($(TARGETOS),Darwin)
  TESTS := $(filter-out hello-exe test3 $(BTESTS),$(TESTS))
 endif
-ifeq (,$(filter arm64 i386 x86-64,$(ARCH)))
+ifeq (,$(filter arm64 i386 x86_64,$(ARCH)))
  TESTS := $(filter-out vla_test-run,$(TESTS))
 endif
 ifeq ($(CONFIG_arm_eabi),yes)
  TESTS := $(filter-out test3,$(TESTS))
 endif
-ifeq (,$(filter i386 x86-64,$(ARCH)))
+ifeq (,$(filter i386 x86_64,$(ARCH)))
  TESTS := $(filter-out dlltest,$(TESTS))
 endif