- Deprecation severity shall be E_STRICT (as commented by ilia)

# Actually this conforms with other messages

Zend/zend_execute_API.c

@@ -864,7 +864,7 @@ int zend_call_function(zend_fcall_info *fci, zend_fcall_info_cache *fci_cache TS
 			zend_error_noreturn(E_ERROR, "Cannot call abstract method %v::%v()", EX(function_state).function->common.scope->name, EX(function_state).function->common.function_name);
 		}
 		if (EX(function_state).function->common.fn_flags & ZEND_ACC_DEPRECATED) {
-			zend_error(E_NOTICE, "Function %s%s%s() is deprecated",
+			zend_error(E_STRICT, "Function %s%s%s() is deprecated",
 				EX(function_state).function->common.scope ? EX(function_state).function->common.scope->name.s : "",
 				EX(function_state).function->common.scope ? "::" : "",
 				EX(function_state).function->common.function_name);

Zend/zend_vm_def.h

@@ -1820,7 +1820,7 @@ ZEND_VM_HELPER(zend_do_fcall_common_helper, ANY, ANY)
 			ZEND_VM_NEXT_OPCODE(); /* Never reached */
 		}
 		if (EX(function_state).function->common.fn_flags & ZEND_ACC_DEPRECATED) {
-			zend_error(E_NOTICE, "Function %v%s%v() is deprecated",
+			zend_error(E_STRICT, "Function %v%s%v() is deprecated",
 				EX(function_state).function->common.scope ? EX(function_state).function->common.scope->name : (zstr)EMPTY_STR,
 				EX(function_state).function->common.scope ? "::" : "",
 				EX(function_state).function->common.function_name);

Zend/zend_vm_execute.h

@@ -146,7 +146,7 @@ static int zend_do_fcall_common_helper_SPEC(ZEND_OPCODE_HANDLER_ARGS)
 			ZEND_VM_NEXT_OPCODE(); /* Never reached */
 		}
 		if (EX(function_state).function->common.fn_flags & ZEND_ACC_DEPRECATED) {
-			zend_error(E_NOTICE, "Function %v%s%v() is deprecated",
+			zend_error(E_STRICT, "Function %v%s%v() is deprecated",
 				EX(function_state).function->common.scope ? EX(function_state).function->common.scope->name : (zstr)EMPTY_STR,
 				EX(function_state).function->common.scope ? "::" : "",
 				EX(function_state).function->common.function_name);