This fixes casting warning and removes the need of that cast at all.

llvm-svn: 286065

Patch switches computing of --build-id hash to tree.

This is the way when input data is splitted by chunks,
hash is computed for each one in threaded/non-threaded way.
At the end hash is conputed for result tree.

With or without -threads the result hash is the same.

Differential revision: https://reviews.llvm.org/D26199

llvm-svn: 286061

A CommonInputSection is a section containing all common symbols.
That was an input section but was abstracted in a different way
than the synthetic input sections because it was written before
the synthetic input section was invented.

This patch rewrites CommonInputSection as a synthetic input section
so that it behaves better with other sections.

llvm-svn: 286053

Differential Revision: https://reviews.llvm.org/D26225

llvm-svn: 285851

We are going to have many more classes for linker-synthesized
input sections, so it's worth to be added to a separate file
than to the file for regular input sections.

llvm-svn: 285740