Merge: b9c16b98d1 b08b6a17bd
* reintegrated debug_eh branch
o the LLVM compiler is now functional for Darwin/x86-64, and also (but less
tested) for Linux/x86-64, Linux/AArch64 and Linux/ARMHF. See
https://wiki.freepascal.org/LLVM for details and the current state
o Dwarf-eh-based "zero-cost" exceptions are available with the regular
code generators for Linux/x86-64 and Linux/i386 if the compiler is
compiled with -dpsabieh