[RuntimeDyld] Add bounds checking to SectionEntry::advanceStubOffset

Summary:
Change SectionEntry to keep track of the size of its underlying
allocation, and use that to bounds check advanceStubOffset.

Reviewers: lhames, andrew.w.kaylor, reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14675

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253919 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed