[llvm] [RISCV] Handle non uimm5 VL constants in isVLKnownLE (PR #156639)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `arc-builder` running on `arc-worker` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/3/builds/21512

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
4.885 [27/18/15] Linking CXX executable unittests/CodeGen/GlobalISel/GlobalISelTests
4.922 [26/18/16] Linking CXX executable unittests/Debuginfod/DebuginfodTests
5.608 [25/18/17] Linking CXX executable unittests/ExecutionEngine/ExecutionEngineTests
5.661 [24/18/18] Linking CXX executable unittests/CodeGen/CGPluginTest/CGPluginTest
5.759 [23/18/19] Linking CXX executable unittests/ExecutionEngine/JITLink/JITLinkTests
6.015 [22/18/20] Linking CXX executable unittests/InterfaceStub/InterfaceStubTests
8.698 [21/18/21] Linking CXX executable unittests/FuzzMutate/FuzzMutateTests
8.781 [20/18/22] Linking CXX executable unittests/Linker/LinkerTests
16.230 [19/18/23] Linking CXX executable unittests/MC/MCTests
17.166 [18/18/24] Linking CXX executable unittests/Passes/Plugins/PluginsTests
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=1217.977089

```

</details>

https://github.com/llvm/llvm-project/pull/156639