simpleperf: fix tests on windows.

The tests fail because Windows doesn't allow deleting opened files.

Also avoid using pid_t in BuildIdRecord, which takes 8 bytes on 64-bit
Windows.

Bug: 175885920
Test: run simpleperf_unit_test.
Change-Id: I84f8fe7a59a4324425a39a3a9fd343e7718d8116
5 files changed