tccgen: nocode_wanted alternatively

tccgen.c: remove any 'nocode_wanted' checks, except in
- greloca(), disables output elf symbols and relocs
- get_reg(), will return just the first suitable reg)
- save_regs(), will do nothing

Some minor adjustments were made where nocode_wanted is set.

xxx-gen.c: disable code output directly where it happens
in functions:
- g(), output disabled
- gjmp(), will do nothing
- gtst(), dto.

x86_64-gen.c

@@ -145,6 +145,8 @@ static int func_ret_sub;
 ST_FUNC void g(int c)
 {
     int ind1;
+    if (nocode_wanted)
+        return;
     ind1 = ind + 1;
     if (ind1 > cur_text_section->data_allocated)
         section_realloc(cur_text_section, ind1);
@@ -213,9 +215,6 @@ void gsym(int t)
     gsym_addr(t, ind);
 }
 
-/* psym is used to put an instruction with a data field which is a
-   reference to a symbol. It is in fact the same as oad ! */
-#define psym oad
 
 static int is64_type(int t)
 {
@@ -227,18 +226,18 @@ static int is64_type(int t)
 /* instruction + 4 bytes data. Return the address of the data */
 ST_FUNC int oad(int c, int s)
 {
-    int ind1;
-
+    int t;
+    if (nocode_wanted)
+        return s;
     o(c);
-    ind1 = ind + 4;
-    if (ind1 > cur_text_section->data_allocated)
-        section_realloc(cur_text_section, ind1);
-    write32le(cur_text_section->data + ind, s);
-    s = ind;
-    ind = ind1;
-    return s;
+    t = ind;
+    gen_le32(s);
+    return t;
 }
 
+/* generate jmp to a label */
+#define gjmp2(instr,lbl) oad(instr,lbl)
+
 ST_FUNC void gen_addr32(int r, Sym *sym, long c)
 {
     if (r & VT_SYM)
@@ -1703,7 +1702,7 @@ void gfunc_epilog(void)
 /* generate a jump to a label */
 int gjmp(int t)
 {
-    return psym(0xe9, t);
+    return gjmp2(0xe9, t);
 }
 
 /* generate a jump to a fixed address */
@@ -1749,7 +1748,10 @@ ST_FUNC void gtst_addr(int inv, int a)
 ST_FUNC int gtst(int inv, int t)
 {
     int v = vtop->r & VT_VALMASK;
-    if (v == VT_CMP) {
+
+    if (nocode_wanted) {
+        ;
+    } else if (v == VT_CMP) {
         /* fast case : can jump directly since flags are set */
 	if (vtop->c.i & 0x100)
 	  {
@@ -1766,11 +1768,11 @@ ST_FUNC int gtst(int inv, int t)
 	    else
 	      {
 	        g(0x0f);
-		t = psym(0x8a, t); /* jp t */
+		t = gjmp2(0x8a, t); /* jp t */
 	      }
 	  }
         g(0x0f);
-        t = psym((vtop->c.i - 16) ^ inv, t);
+        t = gjmp2((vtop->c.i - 16) ^ inv, t);
     } else if (v == VT_JMP || v == VT_JMPI) {
         /* && or || optimization */
         if ((v & 1) == inv) {