MB-44253: Remove try/catch from Executor*::runTask methods

Slightly adapted Dave Rigby's patch:

commit 3d4519d
Author: Dave Rigby <[email protected]>
Date:   Thu Feb 11 14:01:47 2021 +0000

    MB-44253: Remove try/catch from Executor*::runTask methods

    These try/catch blocks prevent unhandled exceptions in GlobalTasks
    from triggering std::terminate, and in turn generating a Breakpad
    minidump with the state of the process when the exception was thrown
    (as opposed to where it was caught).

    Started a discussion with Folly about a more generic way to address
    this (i.e. making the try/catch somehow optional) - see
    facebook#1525 - but in the short-term
    simply remove the invokeCatchingExns() wrapper from our branch.

    (Note: Currently we only use ThreadPoolExecutor and hence we only
    /need/ to change that one, but for consistency / possible future use
    change all instances).

folly/Executor.h

@@ -231,7 +231,11 @@ class Executor {
 
   template <typename F>
   FOLLY_ERASE static void invokeCatchingExns(char const* p, F f) noexcept {
+#if 0
     catch_exception(f, invokeCatchingExnsLog, p);
+#else
+    f();
+#endif
   }
 
  protected: