[llvm] [RISCV] Make RISCVInstrInfo::verifyInstruction stricter for immediate-only operands (PR #170736)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 166756 tests passed
* 2909 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.tools/llvm-exegesis/RISCV/latency-by-load.s</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llvm-exegesis -mode=latency --benchmark-phase=assemble-measured-code -mtriple=riscv64-unknown-linux-gnu --mcpu=generic -opcode-name=LD 2>&1 | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck --check-prefix=TEST1 /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/latency-by-load.s
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/llvm-exegesis -mode=latency --benchmark-phase=assemble-measured-code -mtriple=riscv64-unknown-linux-gnu --mcpu=generic -opcode-name=LD
# note: command had no output on stdout or stderr
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck --check-prefix=TEST1 /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/latency-by-load.s
# .---command stderr------------
# | /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/latency-by-load.s:3:8: error: TEST1: expected string not found in input
# | TEST1: ---
# |        ^
# | <stdin>:1:1: note: scanning from here
# | LD: Not all operands were initialized by the snippet generator for LD opcode.
# | ^
# | 
# | Input file: <stdin>
# | Check file: /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/llvm-exegesis/RISCV/latency-by-load.s
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          1: LD: Not all operands were initialized by the snippet generator for LD opcode. 
# | check:3     X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/170736