[llvm-symbolizer] Add llvm-addr2line

[llvm-symbolizer] Add llvm-addr2line

This adds an alias for llvm-symbolizer with different defaults so that
it can be used as a drop-in replacement for GNU's addr2line.

If a substring "addr2line" is found in the tool's name:
  * it defaults "-i", "-f" and "-C" to OFF;
  * it uses "--output-style=GNU" by default.

Differential Revision: https://reviews.llvm.org/D60067

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358749 91177308-0d34-0410-b5e6-96231b3b80d8