[mjsunit] Disable flaky tests wasm/asm-wasm-{i32,f64}

TBR=mstarzinger@chromium.org

Bug: v8:7899
Change-Id: I0b40e60a234b869737fe89726807ff30d29ce8d6
Reviewed-on: https://chromium-review.googlesource.com/1118161
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54196}

test/mjsunit/mjsunit.status

@@ -834,4 +834,11 @@
   'string-replace-gc': [SKIP],
 }],  # variant == slow_path
 
+##############################################################################
+['arch == x64', {
+  # TODO: Flaky test: crbug.com/v8/7899
+  'wasm/asm-wasm-i32': [SKIP],
+  'wasm/asm-wasm-f64': [SKIP],
+}], # arch == x64
+
 ]