[llvm] [RISCV] Just reporting an error shouldn't generate a crash diagnostic (PR #134040)

[Alex Bradbury via llvm-commits]

asb wrote:

This has a slightly frustrating history. Quite some time ago I tried to clean up cases where we didn't want the crash dialog, but the preference was to try to change the default which led to [this RFC](https://discourse.llvm.org/t/rfc-report-fatal-error-and-the-default-value-of-gencrashdialog/73587) and a lengthy debate. Once it was clear there was no path forwards I probably should have returned to the original approach to adding the argument. Setting GenCrashDiag as you do here seems like a fine incremental improvement to me.



https://github.com/llvm/llvm-project/pull/134040