Move the complex address expression out of DIVariable and into an extra
argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218778 91177308-0d34-0410-b5e6-96231b3b80d8
Revert r218778 while investigating buldbot breakage.
"Move the complex address expression out of DIVariable and into an extra"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218782 91177308-0d34-0410-b5e6-96231b3b80d8
Add an immovable type to test Optional<T>::emplace more rigorously after r218732.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218783 91177308-0d34-0410-b5e6-96231b3b80d8
LTO: Ignore disabled diagnostic remarks

r206400 and r209442 added remarks that are disabled by default.
However, if a diagnostic handler is registered, the remarks are sent
unfiltered to the handler.  This is the right behaviour for clang, since
it has its own filters.

However, the diagnostic handler exposed in the LTO API receives only the
severity and message.  It doesn't have the information to filter by pass
name.  For LTO, disabled remarks should be filtered by the producer.

I've changed `LLVMContext::setDiagnosticHandler()` to take a `bool`
argument indicating whether to respect the built-in filters.  This
defaults to `false`, so other consumers don't have a behaviour change,
but `LTOCodeGenerator::setDiagnosticHandler()` sets it to `true`.

To make this behaviour testable, I added a `-use-diagnostic-handler`
command-line option to `llvm-lto`.

This fixes PR21108.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218784 91177308-0d34-0410-b5e6-96231b3b80d8
Add fptrunc to mips fast-sel

Summary: Implement conversion of 64 to 32 bit floating point numbers (fptrunc) in mips fast-isel

Test Plan:
fptrunc.ll
checked also with 4 internal mips build bot flavors mip32r1/miprs32r2 and at -O0 and -O2

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: rfuhler

Differential Revision: http://reviews.llvm.org/D5553

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218785 91177308-0d34-0410-b5e6-96231b3b80d8
LTO: Add missing target triple from r218784

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218786 91177308-0d34-0410-b5e6-96231b3b80d8