This reapplies r207130 with an additional testcase+and a missing check for
AllocaInst that was missing in one location.
Debug info for optimized code: Support variables that are on the stack and
described by DBG_VALUEs during their lifetime.

Previously, when a variable was at a FrameIndex for any part of its
lifetime, this would shadow all other DBG_VALUEs and only a single
fbreg location would be emitted, which in fact is only valid for a small
range and not the entire lexical scope of the variable. The included
dbg-value-const-byref testcase demonstrates this.

This patch fixes this by
Local
- emitting dbg.value intrinsics for allocas that are passed by reference
- dropping all dbg.declares (they are now fully lowered to dbg.values)
SelectionDAG
- renamed constructors for SDDbgValue for better readability.
- fix UserValue::match() to handle indirect values correctly
- not inserting an MMI table entries for dbg.values that describe allocas.
- lowering dbg.values that describe allocas into *indirect* DBG_VALUEs.
CodeGenPrepare
- leaving dbg.values for an alloca were they are (see comment)
Other
- regenerated/updated instcombine.ll testcase and included source

rdar://problem/16679879
http://reviews.llvm.org/D3374

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207235 91177308-0d34-0410-b5e6-96231b3b80d8
Reapply r207135 without modifications.

Debug info: Let dbg.values inserted by LowerDbgDeclare inherit the location
of the dbg.value. This gets rid of tons of redundant variable DIEs in
subscopes.

rdar://problem/14874886, rdar://problem/16679936

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207236 91177308-0d34-0410-b5e6-96231b3b80d8
PR19554: Fix some memory leaks in DIEHashTest.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207240 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: provide a new generic hint intrinsic

Introduce the llvm.arm.hint(i32) intrinsic that can be used to inject hints into
the instruction stream. This is particularly useful for generating IR from a
compiler where the user may inject an intrinsic (e.g. __yield). These are then
pattern substituted into the correct instruction which already existed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207242 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor some common logic in DwarfUnit::constructVariableDIE and pass non-null DIE by reference to DbgVariable::setDIE

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207244 91177308-0d34-0410-b5e6-96231b3b80d8
[inline cold threshold] Command line argument for inline threshold will
override the default cold threshold.

When we use command line argument to set the inline threshold, the default
cold threshold will not be used. This is in line with how we use
OptSizeThreshold. When we want a higher threshold for all functions, we
do not have to set both inline threshold and cold threshold.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207245 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: remove @llvm.arm.sevl

This intrinsic is no longer needed with the new @llvm.arm.hint(i32) intrinsic
which provides a generic, extensible manner for adding hint instructions.  This
functionality can now be represented as @llvm.arm.hint(i32 5).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207246 91177308-0d34-0410-b5e6-96231b3b80d8