[NFC] [InstCombine] Modify and Added tests for select-of-bittest

Tests that begin with n in select-of-bittest are negative tests.
However, n5 test is different from the intent of the test because
bits in %t and %t2 are the same. This is probably a mistake,
so corrected it.

Also added tests for cases where the and/or/xor might be optimized
if it is placed in the cond and truval of selectInst.

proof : https://alive2.llvm.org/ce/z/KJbbbp

Author: ParkHanbum