All wasm code is compiled now. Hence merge the
{WasmCompiledFrameSummary} into {WasmFrameSummary} and remove the
dispatch. Also, rename {IsWasmCompiled} to {IsWasm} and {AsWasmCompiled}
to {AsWasm}.

R=jkummerow@chromium.org

Bug: v8:10389
Change-Id: I33e413c7d0fa622249563091925b29631472b40c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2187170Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67689}