[spirv] Fail for functions with >255 parameters

Some IR transforms add new parameters to existing functions, which can
cause a valid input shader to exceed SPIR-V limit of 255
parameters. We can't easily fix this, so just fail gracefully and
class it as a spurious failure as per the WGSL spec.

Fixed: 354748060
Change-Id: I31b1d1eddc2b75e237e3f01f967f4bb3e3488cee
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/200014
Reviewed-by: David Neto <dneto@google.com>
Auto-Submit: James Price <jrprice@google.com>
Commit-Queue: David Neto <dneto@google.com>
(cherry picked from commit 3f657b9e679dc3a9f35f4a9f880f5da02ae86478)
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/200275
Reviewed-by: Ken Russell <kbr@google.com>