win32/tccpe: use full dll-path with -run

This allows for example this scenario:

- A dll to be linked with is specified in file.c, where file.c
  and the dll exist in the same directory:
    #pragma comment(lib, "txml")
    #pragma comment(option, "-L{f}")

- tcc is called to run file.c from other, varying directories:
    $ tcc -run some/dir/file.c <args...>

Note that tcc replaces {f} by the currently compiled file's
directory ('some/dir' in this example).

Also:
- tccgen.c: fix last commit for gen_cast.

tccgen.c

@@ -3569,7 +3569,7 @@ again:
             if (ds <= ss)
                 goto done;
             /* ss <= 4 here */
-            if (ds <= 4 && dbt != (VT_SHORT | VT_UNSIGNED) && sbt != VT_BYTE) {
+            if (ds <= 4 && !(dbt == (VT_SHORT | VT_UNSIGNED) && sbt == VT_BYTE)) {
                 gv(RC_INT);
                 goto done; /* no 64bit envolved */
             }

tccpe.c

@@ -825,7 +825,7 @@ static void pe_build_imports(struct pe_info *pe)
 
         dllindex = p->dll_index;
         if (dllindex)
-            name = (dllref = pe->s1->loaded_dlls[dllindex-1])->name;
+            name = tcc_basename((dllref = pe->s1->loaded_dlls[dllindex-1])->name);
         else
             name = "", dllref = NULL;
 
@@ -1763,7 +1763,7 @@ static int pe_load_dll(TCCState *s1, const char *filename)
     if (ret) {
         return -1;
     } else if (p) {
-        index = add_dllref(s1, tcc_basename(filename));
+        index = add_dllref(s1, filename);
         for (q = p; *q; q += 1 + strlen(q))
             pe_putimport(s1, index, q, 0);
         tcc_free(p);