[wasm] Update OWNERS

Add jkummerow, thibaudm, zhin; drop titzer.
Also make src/wasm/OWNERS the source of truth and let test-specific
OWNERS files refer to that.

No-Try: true
Change-Id: I9862ae452970e20b7842269721ad6a7953f275fc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1989827
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65636}

src/wasm/OWNERS

@@ -3,7 +3,9 @@ bbudge@chromium.org
 binji@chromium.org
 clemensb@chromium.org
 gdeepti@chromium.org
-titzer@chromium.org
+jkummerow@chromium.org
+thibaudm@chromium.org
+zhin@chromium.org
 
 per-file wasm-js.*=adamk@chromium.org
 

test/cctest/wasm/OWNERS

-ahaas@chromium.org
-clemensb@chromium.org
-titzer@chromium.org
+file:../../../src/wasm/OWNERS
 
 # COMPONENT: Blink>JavaScript>WebAssembly

test/mjsunit/wasm/OWNERS

-ahaas@chromium.org
-clemensb@chromium.org
-titzer@chromium.org
+file:../../../src/wasm/OWNERS

test/unittests/wasm/OWNERS

-ahaas@chromium.org
-clemensb@chromium.org
-titzer@chromium.org
+file:../../../src/wasm/OWNERS
 
 # COMPONENT: Blink>JavaScript>WebAssembly

test/wasm-spec-tests/OWNERS

-ahaas@chromium.org
-clemensb@chromium.org
+file:../../src/wasm/OWNERS
 
 # COMPONENT: Blink>JavaScript>WebAssembly

tools/wasm-compilation-hints/OWNERS

-clemensb@chromium.org
+file:../../src/wasm/OWNERS