makefile: Add a new install-compiler-lib target
makefile: Add a new install-compiler-lib target

This makes it easier to build dynlink-able libraries by collecting all compiler
CMIs into a single folder.

Co-Authored-By: da39a3ee5e6b4b0d3255bfef95601890afd80709@victor-dumitrescu

A-Manning/FStar,A-Manning/FStar,FStarLang/FStar,A-Manning/FStar,FStarLang/FStar,FStarLang/FStar