[RISCV] Add more tests for (and (shl x, C2), C1) that can be improved by using...

[RISCV] Add more tests for (and (shl x, C2), C1) that can be improved by using a pair of shifts. NFC

These tests have C1 as a shifted mask having no leading zeros and
C3 trailing zeros. If C3 is more than C2, we can select this as
(slli (srli x, C3-C2), C3).