[PDB] Implement more find methods for PDB symbols

[PDB] Implement more find methods for PDB symbols

Summary:
Add additional find methods on PDB raw symbols.

findChildrenByAddr()
findChildrenByVA()
findInlineFramesByAddr()
findInlineFramesByVA()
findInlineLines()
findInlineLinesByAddr()
findInlineLinesByRVA()
findInlineLinesByVA()

Reviewers: zturner, llvm-commits

Reviewed By: zturner

Differential Revision: https://reviews.llvm.org/D43637

llvm-svn: 325824