Fixed bugs in "FastVector" class. Bugs: - items resources may not be freed after resizing to a lesser size. - reusing capacity may use old values for the new items. Fixed by resting removed items to default values. Alternative fix is to disallow dangerous operations on non trivially constructible/destructible types. Bug: angleproject:8021 Test: angle_unittests --gtest_filter="FastVector.DestroyOldItems" Test: angle_unittests --gtest_filter="FastVector.ReuseCapacity" Change-Id: I8bc616a9476608c9301e3f7af3a0d504e7e2d2db Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4249960 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Igor Nazarov <i.nazarov@samsung.com>