Add the MachineInstrSpan class.

MachineInstrSpan is initialized with a MachineBasicBlock::iterator,
and is intended to track which instructions are inserted before/after
that instruction from the time the MachineInstrSpan is created.

It provides a begin()/end() interface to walk the range of
instructions inserted around the initial instruction (including that
initial instruction).

It also provides a getInitial() interface to return the initial
iterator.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188436 91177308-0d34-0410-b5e6-96231b3b80d8
Auto-compute live intervals on demand.

When new virtual registers are created during splitting/spilling, defer
creation of the live interval until we need to use the live interval.

Along with the recent commits to notify LiveRangeEdit when new virtual
registers are created, this makes it possible for functions like
TargetInstrInfo::loadRegFromStackSlot() and
TargetInstrInfo::storeRegToStackSlot() to create multiple virtual
registers as part of the process of generating loads/stores for
different register classes, and then have the live intervals for those
new registers computed when they are needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188437 91177308-0d34-0410-b5e6-96231b3b80d8
Replace getValueType().getSimpleVT() with getSimpleValueType(). Also remove one weird cast from MVT->EVT just to call getSimpleVT().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188441 91177308-0d34-0410-b5e6-96231b3b80d8
Replace getValueType().getSimpleVT() with getSimpleValueType().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188442 91177308-0d34-0410-b5e6-96231b3b80d8
Fixed typo in CMakeLists.txt.

We were marking both LLVMBUILDOUTPUT and LLVMBUILDERRORS as
ERROR_VARIABLES when clearly LLVMBUILDOUTPUT should be marked as
OUTPUT_VARIABLE.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188444 91177308-0d34-0410-b5e6-96231b3b80d8
Use MVT in place of EVT in more X86 operation lowering functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188445 91177308-0d34-0410-b5e6-96231b3b80d8

Conflicts:

	lib/Target/X86/X86ISelLowering.cpp

Change-Id: Ie8e54a7622d203f0f1860f7b6ddad670776325ca