[BOLT] Delay indirect call pointer setup (#204229)
There is a race in the instrumentation runtime during setup. The setup
initializes the function pointers for indirect call instrumentation
before the indirect call counters array. If the application spawns a
background thread through a constructor (as does jemalloc), the
background thread has a chance to derefence that uninitialized array
pointer. Defer initialization of these function pointers to prevent this
race.
Fixes #198181.
Co-authored-by: Fabian Parzefall <parzefall@meta.com>
