IR: Sink MDNode::Hash down to GenericMDNode::Hash

Part of PR21532.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222212 91177308-0d34-0410-b5e6-96231b3b80d8
IndVarSimplify: Allow LFTR to fire more often

I added a pessimization in r217102 to prevent miscompiles when the
incremented induction variable was used in a comparison; it would be
poison.

Try to use the incremented induction variable more often when we can be
sure that the increment won't end in poison.

Differential Revision: http://reviews.llvm.org/D6222

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222213 91177308-0d34-0410-b5e6-96231b3b80d8
SimplifyCFG: Range'ify some for-loops. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222215 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-readobj: Don't print the Characteristics field as the Subsystem

We claimed that we were printing the Subystem field when we were
actually printing the Characteristics field.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222216 91177308-0d34-0410-b5e6-96231b3b80d8
Allow DwarfCompileUnit::constructImportedEntityDIE to instanciate a GlobalVariable DIE.

Usually global variables are in a retain list and instanciated before
any call to constructImportedEntityDIE is made. This isn't true for
forward declarations though.
The testcase for this change is generated by a clang patched to emit
such forward declarations (patch at http://reviews.llvm.org/D6173
which will land soon). The updated testcase tests more than just
global variables, it now tests every type of 'using' clause we
support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222217 91177308-0d34-0410-b5e6-96231b3b80d8