Improve efficiency of macro concatenation

As per grischka comment, always output a space after macro concatenation
instead of trying to detect if it's necessary as the current approach
has a huge cost.

tccpp.c

@@ -2910,32 +2910,8 @@ static inline int *macro_twosharps(const int *macro_str)
             }
         }
         if (tok != TOK_NOSUBST) {
-            const int *oldptr;
+            tok_str_add2(&macro_str1, tok, &tokc);
-            CValue cval;
+            tok = ' ';
-
-            /* Check if a space need to be added after ## concatenation in
-               order to avoid misinterpreting the newly formed token
-               followed by the next token as being a single token (see
-               macro_concat test) */
-            cstr_new(&cstr);
-            cstr_cat(&cstr, get_tok_str(tok, &tokc));
-            oldptr = ptr;
-            TOK_GET(&t, &ptr, &cval);
-            ptr = oldptr;
-            cstr_cat(&cstr, get_tok_str(t, &cval));
-            cstr_ccat(&cstr, '\0');
-            t = tok;
-            cval = tokc;
-            tcc_open_bf(tcc_state, ":paste:", cstr.size);
-            memcpy(file->buffer, cstr.data, cstr.size);
-            next_nomacro1();
-            if (!*file->buf_ptr) {
-                tok_str_add2(&macro_str1, t, &cval);
-                tok = ' ';
-            }
-            tcc_close();
-            cstr_free(&cstr);
-
             start_of_nosubsts = -1;
         }
         tok_str_add2(&macro_str1, tok, &tokc);