WriterPECOFF

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@195794 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "WriterPECOFF"

This reverts accidental commit r195794.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@195795 91177308-0d34-0410-b5e6-96231b3b80d8
[PECOFF] Add a generic section writer.

Instead of having multiple SectionChunks for each section (.text, .data,
.rdata and .bss), we could have one chunk writer that can emit any sections.
This patch does that -- removing all section-sepcific chunk writers and
replace them with one "generic" writer.

This change should simplify the code because it eliminates similar-but-
slightly-different classes.

It also fixes an issue in the previous design. Before this patch, we could
emit only limited set of sections (i.e. .text, .data, .rdata and .bss). With
this patch, we can emit any sections.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@195797 91177308-0d34-0410-b5e6-96231b3b80d8