[RISCV] For RV32C, disassembly of c.slli should fail when immediate > 31 (#133713)

Fixes #133712.

The change causes `c.slli` instructions whose immediate has bit 5 set to
be rejected when disassembling RV32C. Added a test to exhaustively cover
c.slli for 32 bit targets. A minor tweak to make the debug output a
little more readable.

The spec. (20240411) says:

> For RV32C, shamt[5] must be zero; the code points with shamt[5]=1 are
designated for custom extensions. For RV32C and RV64C, the shift amount
must be non-zero; the code points with shamt=0 are HINTs. For all base
ISAs, the code points with rd=x0 are HINTs, except those with shamt[5]=1
in RV32C.

0 files changed, 0 insertions, 0 deletions