This adds functionality for undefined atoms from dynamic libraries to be added
to the list of undefined atoms. 

The processing of undefined atoms from dynamic libraries is controlled by
use-shlib-undefines command line option. 

This patch also adds additional command line arguments to allow/disallow
unresolved symbols from shared libraries and mimics GNU ld behavior.



git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179257 91177308-0d34-0410-b5e6-96231b3b80d8
[test] fix failing test, the test was not accounting for - in the path

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179260 91177308-0d34-0410-b5e6-96231b3b80d8
[test] missing underscore while checking for test output

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179264 91177308-0d34-0410-b5e6-96231b3b80d8
Replace elf-dump with llvm-readobj in lld tests

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179364 91177308-0d34-0410-b5e6-96231b3b80d8
[Core] Add parallel infrastructure to lld.

Uses ConcRT and PPL on Windows.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179397 91177308-0d34-0410-b5e6-96231b3b80d8
Moved llvm_unreachable out of switch blocks to avoid the "control reaches end of non-void function" warning.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179590 91177308-0d34-0410-b5e6-96231b3b80d8
Distinguish between unsupported and unrecognised flavours.

Suggested by Nick Kledzik in reference to r179590.


git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@179617 91177308-0d34-0410-b5e6-96231b3b80d8
[Core] Allow weak symbols in shared library when linking.

Patch by Rui Ueyama.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@180209 91177308-0d34-0410-b5e6-96231b3b80d8