Add definition for ELF dynamic tag DT_SYMTAB_SHNDX.
Add definition for ELF dynamic tag DT_SYMTAB_SHNDX.

DT_SYMTAB_SHNDX is defined in generic-abi:

http://www.sco.com/developers/gabi/latest/ch5.dynamic.html

Patch by Rahul Chaudhry!

Differential Revision: https://reviews.llvm.org/D47803

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@334149 91177308-0d34-0410-b5e6-96231b3b80d8

GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm