The request is mentioned on D129053. I feel that having this functionality is
mildly useful (not strong).
* Rename .ctors to .init_array and change sh_type to SHT_INIT_ARRAY (GNU objcopy
detects the special name but we don't).
* Craft tests for a new SHT_LLVM_* extension
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D129337
Fangrui Song