tcc.h: declare CValue.tab[LDOUBLE_SIZE/4]

Should fix some warnings wrt. access out of array bounds.

tccelf.c: fix "static function unused" warning
x86_64-gen.c: fix "ctype.ref uninitialzed" warning and cleanup
tcc-win32.txt: remove obsolete limitation notes.

lib/Makefile

@@ -28,6 +28,7 @@ ifndef TARGET
  endif
  endif
  endif
+ BCHECK_O = bcheck.o
 endif
 
 DIR = $(TARGET)
@@ -38,8 +39,6 @@ cross : $(DIR)/libtcc1.a
 native : TCC = $(TOP)/tcc$(EXESUF)
 cross : TCC = $(TOP)/$(TARGET)-tcc$(EXESUF)
 
-BCHECK_O = bcheck.o
-
 I386_O = libtcc1.o alloca86.o alloca86-bt.o $(BCHECK_O)
 X86_64_O = libtcc1.o alloca86_64.o
 WIN32_O = $(I386_O) crt1.o wincrt1.o dllcrt1.o dllmain.o chkstk.o