AsmParser: Don't crash on an ill-formed MDNodeVector

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224053 91177308-0d34-0410-b5e6-96231b3b80d8
[InstCombine][X86] Improved folding of calls to Intrinsic::x86_sse4a_insertqi.

This patch teaches the instruction combiner how to fold a call to 'insertqi' if
the 'length field' (3rd operand) is set to zero, and if the sum between
field 'length' and 'bit index' (4th operand) is bigger than 64.

From the AMD64 Architecture Programmer's Manual:
1. If the sum of the bit index + length field is greater than 64, then the
   results are undefined;
2. A value of zero in the field length is defined as a length of 64.

This patch improves the existing combining logic for intrinsic 'insertqi'
adding extra checks to address both point 1. and point 2.

Differential Revision: http://reviews.llvm.org/D6583


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224054 91177308-0d34-0410-b5e6-96231b3b80d8
AsmParser: Don't crash on an ill-formed MDNodeVector

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224056 91177308-0d34-0410-b5e6-96231b3b80d8
LeakDetector: Simplify code and fix comments, NFC

Rather than requiring overloads in the wrapper and the impl, just
overload the impl and use templates in the wrapper.  This makes it less
error prone to add more overloads (`void *` defeats any chance the
compiler has at noticing bugs, so the easier the better).

At the same time, correct the comment that was lying about not changing
functionality for `Value`.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224058 91177308-0d34-0410-b5e6-96231b3b80d8