[BOLT] Add static binary support

Summary:
Accept binaries without dynamic section/segment as a valid input.

Modify the check for invalid debug info "executables" that are result of
running "objcopy --only-keep-debug". Instead of checking for an empty
dynamic segment, check that ".text" is mapped into a valid segment.

Move SegmentMapInfo inside BinaryContext.

Fixes facebookincubator/BOLT#91

Temporarily removing issue*.test tests that use yaml2obj and operate on
fake binaries.

(cherry picked from FBD22271481)