tccgen: fix long long -> char/short cast

This was causing assembler bugs in a tcc compiled by itself
at i386-asm.c:352 when ExprValue.v was changed to uint64_t:

    if (op->e.v == (int8_t)op->e.v)
        op->type |= OP_IM8S;

A general test case:

    #include <stdio.h>
    int main(int argc, char **argv)
    {
        long long ll = 4000;
        int i = (char)ll;
        printf("%d\n", i);
        return 0;
    }

Output was "4000", now "-96".

Also: add "asmtest2" as asmtest with tcc compiled by itself

tccgen.c

@@ -1948,7 +1948,10 @@ static void force_charshort_cast(int t)
         vpushi((1 << bits) - 1);
         gen_op('&');
     } else {
-        bits = 32 - bits;
+        if ((vtop->type.t & VT_BTYPE) == VT_LLONG)
+            bits = 64 - bits;
+        else
+            bits = 32 - bits;
         vpushi(bits);
         gen_op(TOK_SHL);
         /* result must be signed or the SAR is converted to an SHL

tests/Makefile

@@ -21,7 +21,7 @@ TESTS = \
 BTESTS = test1b test3b btest
 
 # test4 -- problem with -static
-# asmtest -- minor differences with gcc
+# asmtest / asmtest2 -- minor differences with gcc
 # btest -- works on i386 (including win32)
 
 # bounds-checking is supported only on i386
@@ -173,12 +173,15 @@ asmtest.ref: asmtest.S
 	$(CC) -Wa,-W -o asmtest.ref.o -c asmtest.S
 	objdump -D asmtest.ref.o > asmtest.ref
 
-asmtest: asmtest.ref
+asmtest asmtest2: asmtest.ref
 	@echo ------------ $@ ------------
-	$(TCC) -c asmtest.S
+	$(TCC) $(MAYBE_RUN_TCC) -c asmtest.S
 	objdump -D asmtest.o > asmtest.out
 	@if diff -u --ignore-matching-lines="file format" asmtest.ref asmtest.out ; then echo "ASM Auto Test OK"; fi
 
+# test assembler with tcc compiled by itself
+asmtest2: MAYBE_RUN_TCC = $(RUN_TCC)
+
 # Check that code generated by libtcc is binary compatible with
 # that generated by CC
 abitest-cc$(EXESUF): abitest.c $(LIBTCC)

tests/asmtest.S

@@ -696,6 +696,7 @@ int $0x10
     inc %eax
 #endif
 
+#ifndef _WIN32
 ft1: ft2: ft3: ft4: ft5: ft6: ft7: ft8: ft9:
     xor %eax, %eax
     ret
@@ -708,6 +709,7 @@ ft1: ft2: ft3: ft4: ft5: ft6: ft7: ft8: ft9:
 .type ft6,@function
 .type ft7,%function
 .type ft8,"function"
+#endif
 
     pause
 .rept 6