[LiveDebugValues] Emit the debug entry values

[LiveDebugValues] Emit the debug entry values

Emit replacements for clobbered parameters location if the parameter
has unmodified value throughout the funciton. This is basic scenario
where we can use the debug entry values.

([12/13] Introduce the debug entry values.)

Co-authored-by: Ananth Sowda <asowda@cisco.com>
Co-authored-by: Nikola Prica <nikola.prica@rt-rk.com>
Co-authored-by: Ivan Baev <ibaev@cisco.com>
Differential Revision: https://reviews.llvm.org/D58042

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364553 91177308-0d34-0410-b5e6-96231b3b80d8