[llvm] [llvm-mca] Abort on parse error without -skip-unsupported-instructions (PR #90474)

[Michael Maitland via llvm-commits]

michaelmaitland wrote:

To ignore parse errors is to accept programs that are not well formed. Do we really want to support this?

The proposal doesn't account for this concern:

> I'm more worried about passing something totally incorrect, like passing not enough registers, or incorrect types of registers, or even mnemonics that don't exist.

What do you think about this proposal:
* the test case should use a different instruction sequence that both CPU can support, or the test case should be split into two cases, one for each CPU.
* -skip-unsupported-instructions only skips instructions that cannot be converted from MCInst to mca::Instruction



https://github.com/llvm/llvm-project/pull/90474