Zend/Optimizer/block_pass.c: remove code disabled with #if 0 (#21791)

It has been that way since the initial public release of the optimizer in
528006a and survived through the merging as
ext/opcache (34d3202) and then moving it into
core (#6642). If it hasn't been needed in the last 13 years, should be safe to
drop.

Author: DanielEScherzer

Zend/Optimizer/block_pass.c

@@ -344,59 +344,6 @@ static void zend_optimize_block(zend_basic_block *block, zend_op_array *op_array
 				}
 				break;
 
-#if 0
-		/* pre-evaluate functions:
-		   constant(x)
-		   function_exists(x)
-		   extension_loaded(x)
-		   BAD: interacts badly with Accelerator
-		*/
-		if((opline->op1_type & IS_VAR) &&
-		   VAR_SOURCE(opline->op1) && VAR_SOURCE(opline->op1)->opcode == ZEND_DO_CF_FCALL &&
-		   VAR_SOURCE(opline->op1)->extended_value == 1) {
-			zend_op *fcall = VAR_SOURCE(opline->op1);
-			zend_op *sv = fcall-1;
-			if(sv >= block->start_opline && sv->opcode == ZEND_SEND_VAL &&
-			   sv->op1_type == IS_CONST && Z_TYPE(OPLINE_OP1_LITERAL(sv)) == IS_STRING &&
-			   Z_LVAL(OPLINE_OP2_LITERAL(sv)) == 1
-			   ) {
-				zval *arg = &OPLINE_OP1_LITERAL(sv);
-				char *fname = FUNCTION_CACHE->funcs[Z_LVAL(ZEND_OP1_LITERAL(fcall))].function_name;
-				size_t flen = FUNCTION_CACHE->funcs[Z_LVAL(ZEND_OP1_LITERAL(fcall))].name_len;
-				if((flen == sizeof("function_exists")-1 && zend_binary_strcasecmp(fname, flen, "function_exists", sizeof("function_exists")-1) == 0) ||
-						  (flen == sizeof("is_callable")-1 && zend_binary_strcasecmp(fname, flen, "is_callable", sizeof("is_callable")-1) == 0)
-						  ) {
-					zend_function *function;
-					if((function = zend_hash_find_ptr(EG(function_table), Z_STR_P(arg))) != NULL) {
-						literal_dtor(arg);
-						MAKE_NOP(sv);
-						MAKE_NOP(fcall);
-						LITERAL_BOOL(opline->op1, 1);
-						opline->op1_type = IS_CONST;
-					}
-				} else if(flen == sizeof("constant")-1 && zend_binary_strcasecmp(fname, flen, "constant", sizeof("constant")-1) == 0) {
-					zval c;
-					if (zend_optimizer_get_persistent_constant(Z_STR_P(arg), &c, true ELS_CC)) {
-						literal_dtor(arg);
-						MAKE_NOP(sv);
-						MAKE_NOP(fcall);
-						ZEND_OP1_LITERAL(opline) = zend_optimizer_add_literal(op_array, &c);
-						/* no copy ctor - get already copied it */
-						opline->op1_type = IS_CONST;
-					}
-				} else if(flen == sizeof("extension_loaded")-1 && zend_binary_strcasecmp(fname, flen, "extension_loaded", sizeof("extension_loaded")-1) == 0) {
-					if(zend_hash_exists(&module_registry, Z_STR_P(arg))) {
-						literal_dtor(arg);
-						MAKE_NOP(sv);
-						MAKE_NOP(fcall);
-						LITERAL_BOOL(opline->op1, 1);
-						opline->op1_type = IS_CONST;
-					}
-				}
-			}
-		}
-#endif
-
 			case ZEND_FETCH_LIST_R:
 			case ZEND_FETCH_LIST_W:
 				if (opline->op1_type & (IS_TMP_VAR|IS_VAR)) {