[WebAssembly] Remove dead code from LEB compression pass.
[WebAssembly] Remove dead code from LEB compression pass.

There are only certain relocation types that can exist in the
wasm code section and they are all LEB types.  Remove the dead
code for handling the other (I32) reloc types.

Differential Revision: https://reviews.llvm.org/D47226

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@333030 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld