[BOLT] Split functions with exceptions in shared objects and PIEs

[BOLT] Split functions with exceptions in shared objects and PIEs

Add functionality to allow splitting code with C++ exceptions in shared
libraries and PIEs. To overcome a limitation in exception ranges format,
for functions with fragments spanning multiple sections, add trampoline
landing pads in the same section as the corresponding throwing range.

Reviewed By: Amir

Differential Revision: https://reviews.llvm.org/D127936