Just a note regarding these:
/home/mast/Pike/no-changes-7.7/src/testsuite.in:11: Test 9 (shift 0) (CRNL) failed (expected eval error). Got 0 1: mixed a() { (string) ({0x80000000}); } 2:
/home/mast/Pike/no-changes-7.7/src/testsuite.in:13: Test 11 (shift 2) (CRNL) failed (expected eval error). Got 0 1: mixed a() { (string) ({-0x80000001}); } 2:
The problem here is not the casting or that it doesn't throw an error as it should, but rather that the optimizer or pike_test.pike or something makes the error disappear.