[WebAssembly][lld] control __data_end export with config->shared
[WebAssembly][lld] control __data_end export with config->shared

Summary:
Emscripten expects `__data_end` to show up in PIC code as long as it's not
linked with `--shared`.

Currently, Emscripten breaks with latest LLVM because `__data_end` is controlled
by `config->isPic` instead of `config->shared`.`

Reviewers: tlively, sbc100

Reviewed By: sbc100

Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65980

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@368361 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld