[build] Add flag-utils headers to wasm_test_common

Adds test/common/flag-utils.h and test/common/wasm/flag-utils.h to
wasm_test_common to reduce the number of gn check errors by 4.

Bug: v8:7330
Change-Id: I94e11130c4b96972604cabbaa019617cb1f8f67a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2727404
Commit-Queue: Dan Elphick <delphick@chromium.org>
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73124}

BUILD.gn

@@ -5603,6 +5603,8 @@ v8_fuzzer("regexp_fuzzer") {
 if (v8_enable_webassembly) {
   v8_source_set("wasm_test_common") {
     sources = [
+      "test/common/flag-utils.h",
+      "test/common/wasm/flag-utils.h",
       "test/common/wasm/wasm-interpreter.cc",
       "test/common/wasm/wasm-interpreter.h",
       "test/common/wasm/wasm-module-runner.cc",