Revert "[tsan] Fix GCC 8.3 build after D107911"

This reverts commit 797fe59e.

The use of "EventType type : 3" is replicated for all Event structs and
therefore was still present. As a result this still caused failures on
older GCCs (9.2 or 8.3 or earlier).

The particular bot that was failing due to buggy GCC was fixed by
fef39cc4.

Therefore, no reason to keep the workaround around; revert it.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D108192