Better to have a descriptive compiler error message than weird missing symbols.

Bug: b/147359661
Change-Id: I66c0e5beb1e94f79210528867c990ab3e0f8b0ae
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39949Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>