py/emitnative: Let emitters know the compiled entity's name.

This commit introduces an optional feature to provide to native emitters
the fully qualified name of the entity they are compiling.

This is achieved by altering the generic ASM API to provide a third
argument to the entry function, containing the name of the entity being
compiled.  Currently only the debug emitter uses this feature, as it is
not really useful for other emitters for the time being; in fact the
macros in question just strip the name away.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

py/emitndebug.c

@@ -108,8 +108,8 @@ static void asm_debug_end_pass(asm_debug_t *as) {
     (void)as;
 }
 
-static void asm_debug_entry(asm_debug_t *as, int num_locals) {
-    asm_debug_printf(as, "ENTRY(num_locals=%d)\n", num_locals);
+static void asm_debug_entry(asm_debug_t *as, int num_locals, char *name) {
+    asm_debug_printf(as, "ENTRY(%s, num_locals=%d)\n", name != NULL ? name : "?", num_locals);
 }
 
 static void asm_debug_exit(asm_debug_t *as) {
@@ -195,8 +195,8 @@ static void asm_debug_setcc_reg_reg_reg(asm_debug_t *as, int op, int reg1, int r
 
 #define ASM_T               asm_debug_t
 #define ASM_END_PASS        asm_debug_end_pass
-#define ASM_ENTRY(as, num_locals) \
-    asm_debug_entry(as, num_locals)
+#define ASM_ENTRY(as, num_locals, name) \
+    asm_debug_entry(as, num_locals, name)
 #define ASM_EXIT(as) \
     asm_debug_exit(as)