runtime/pprof: TestCPUProfileMultithreaded is flaky

[lexprfuncall]

I get the following test failures somewhat regularly on my 16 core, 32 thread Linux
machine

--- FAIL: TestCPUProfileMultithreaded (0.69 seconds)
        pprof_test.go:129: crc32.ChecksumIEEE: 10
        pprof_test.go:129: crc32.Update: 58
        pprof_test.go:139: crc32.ChecksumIEEE has 10 samples out of 68, want at least 11, ideally 34

The numbers following crc32.ChecksumIEEE and crc32.Update vary somewhat but the error is
the same.

[lexprfuncall]

Comment 1:

For what it's worth, I have observed this failure with 8g and 6g though the failure is
more frequent with 6g.

[rsc]

Comment 2:

Labels changed: added go1.3maybe.

[rsc]

Comment 3:

Labels changed: added release-none, removed go1.3maybe.

[rsc]

Comment 4:

Labels changed: added repo-main.

[rsc]

Comment 5:

Status changed to Fixed.