The InterpreterAssembler needs to specify a specific CallDescriptor type
instead of using the SimplifiedCDescriptor type. This CL makes it possible
to specify the CallDescriptor used by the RawMachineAssembler instead of
specifying a MachineSignature.
Also removes instruction-selector-tester.h which was erroneously resurrected
at some point.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1235313002
Cr-Commit-Position: refs/heads/master@{#29777}