Summary:
In this patch, `ISD::RETURNADDR` is lowered on the emscripten target
to the new Emscripten runtime function `emscripten_return_address`, which
implements the functionality.
Patch by Guanzhong Chen
Reviewers: tlively, aheejin
Reviewed By: tlively
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62210
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361454 91177308-0d34-0410-b5e6-96231b3b80d8
Thomas Lively