Put RTDyldMemoryManager into its own file, and make it linked into 
libExecutionEngine. Move method implementations that aren't specific to 
allocation out of SectionMemoryManager and into RTDyldMemoryManager.

This is in preparation for exposing RTDyldMemoryManager through the C 
API.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182407 91177308-0d34-0410-b5e6-96231b3b80d8