[cpu-profiler] Enable deopt test

There is a race in the way we handle deopts that made this test flaky.
The race is not hugely important to fix, and is difficult without
breaking something else.

The best thing to do here is update the test to reflect reality so we
can get the test coverage back.

This updates the test so that the deopt reason can be found either
on the first or second level function. The test assumed it would
always be available on the second level function in the profile,
but if we get a regular profile tick at the exact wrong time, we
could end up with the deopt info getting attached to the first level
function. So we accept either.

Bug: v8:5193
Change-Id: Ia43880ebafd1341a514b3143dc215514b5dccf15
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2594775Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71797}

test/cctest/cctest.status

@@ -71,7 +71,6 @@
   'test-heap/OutOfMemory': [SKIP],
 
   # BUG(5193). The cpu profiler tests are notoriously flaky.
-  'test-cpu-profiler/CollectDeoptEvents': [SKIP],
   'test-cpu-profiler/CollectCpuProfile': [SKIP],
   'test-cpu-profiler/JsNative1JsNative2JsSample': [SKIP],
   'test-cpu-profiler/JsNativeJsRuntimeJsSample': [SKIP],

test/cctest/test-cpu-profiler.cc

@@ -2418,7 +2418,10 @@ const char* GetBranchDeoptReason(v8::Local<v8::Context> context,
   v8::CpuProfile* profile = reinterpret_cast<v8::CpuProfile*>(iprofile);
   const ProfileNode* iopt_function = nullptr;
   iopt_function = GetSimpleBranch(context, profile, branch, length);
-  CHECK_EQ(1U, iopt_function->deopt_infos().size());
+  if (iopt_function->deopt_infos().size() == 0) {
+    iopt_function = iopt_function->parent();
+  }
+  CHECK_LE(1U, iopt_function->deopt_infos().size());
   return iopt_function->deopt_infos()[0].deopt_reason;
 }
 
@@ -2492,7 +2495,8 @@ TEST(CollectDeoptEvents) {
       .ToLocalChecked();
   i::CpuProfile* iprofile = iprofiler->GetProfile(0);
   iprofile->Print();
-  /* The expected profile
+  /* The expected profile. Note that the deopt reasons can hang off either of
+     the two nodes for each function, depending on the exact timing at runtime.
   [Top down]:
       0  (root) 0 #1
      23     32 #2