Fix long double to long long for x86_64

Author: hermantb

tcctok.h

@@ -290,6 +290,9 @@
      DEF(TOK___fixdfdi, "__fixdfdi")
      DEF(TOK___fixxfdi, "__fixxfdi")
 #endif
+#if defined TCC_TARGET_X86_64
+     DEF(TOK___fixxfdi, "__fixxfdi")
+#endif
 
 #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64
      DEF(TOK_alloca, "alloca")

x86_64-gen.c

@@ -2153,6 +2153,15 @@ void gen_cvt_ftoi(int t)
     ft = vtop->type.t;
     bt = ft & VT_BTYPE;
     if (bt == VT_LDOUBLE) {
+	if (t != VT_INT) {
+	    vpush_helper_func(TOK___fixxfdi);
+	    vswap();
+	    gfunc_call(1);
+	    vpushi(0);
+	    vtop->r = REG_IRET;
+	    vtop->r2 = REG_IRE2;
+	    return;
+	}
         gen_cvt_ftof(VT_DOUBLE);
         bt = VT_DOUBLE;
     }