Reland "[wasm] Move serialization tests to own file"

This is a reland of c2f1090d, fixing jumbo builds.

Original change's description:
> [wasm] Move serialization tests to own file
>
> Move out all serialization related tests to
> {test-wasm-serialization.cc}, to reduce the size of
> {test-run-wasm-module.cc}.
>
> R=titzer@chromium.org
>
> Bug: v8:7754
> Change-Id: I0b2133baf69e2557df27d1733cc267d1d4cf7452
> Reviewed-on: https://chromium-review.googlesource.com/1107980
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#53909}

TBR=titzer@chromium.org

Bug: v8:7754
Change-Id: Ic0bb02b1b782676c6100daa2d588adce8b54c388
Reviewed-on: https://chromium-review.googlesource.com/1109838Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53919}

test/cctest/BUILD.gn

@@ -249,6 +249,7 @@ v8_source_set("cctest_sources") {
     "wasm/test-wasm-breakpoints.cc",
     "wasm/test-wasm-codegen.cc",
     "wasm/test-wasm-interpreter-entry.cc",
+    "wasm/test-wasm-serialization.cc",
     "wasm/test-wasm-stack.cc",
     "wasm/test-wasm-trap-position.cc",
     "wasm/wasm-atomics-utils.h",