Work around bugs in MSVC "14" CTP 3's conversion logic

It appears to ignore or find ambiguous MachineInstrBuilder's conversion
operators that allow conversion to MachineInstr* and
MachineBasicBlock::bundle_iterator.

As a workaround, add an explicit way to get the MachineInstr.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221017 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "R600: Make sure to inline all internal functions"

This reverts commit r220996.

It introduced layering violations causing link errors in many
configurations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221020 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "R600: Add missing file to CMakeLists.txt"

This reverts commit r220998.

It should've been reverted with the other change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221021 91177308-0d34-0410-b5e6-96231b3b80d8
IR: MDNode => Value: Add Instruction::getMDNode()

Add `Instruction::getMDNode()` that casts to `MDNode` before changing
`Instruction::getMetadata()` to return `Value`.  This avoids adding
`cast_or_null<MDNode>` boiler-plate throughout the code.

Part of PR21433.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221023 91177308-0d34-0410-b5e6-96231b3b80d8
IR: MDNode => Value: Instruction::getMetadata()

Change `Instruction::getMetadata()` to return `Value` as part of
PR21433.

Update most callers to use `Instruction::getMDNode()`, which wraps the
result in a `cast_or_null<MDNode>`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221024 91177308-0d34-0410-b5e6-96231b3b80d8