[PECOFF] Remove COFF header from PE header for simplicity.

COFF header is always present both in executable and in object file. PE header
is present only in executable. So the natural way to handle PE/COFF file is
treating COFF is mandatory header and PE is optional. Current data structre
does not allow it, because PE header includes COFF header. Removing COFF
header will simplify the code to handle PE/COFF files.

Reviewers: Bigcheese

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D952

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183788 91177308-0d34-0410-b5e6-96231b3b80d8
Make host ARM CPU feature detection independent of the vendor

For ARM on linux we use /proc/cpuinfo to detect the host CPU's features.
Linux derives these values without ever looking at the vendor of the
specific CPU implementation. Hence, it adds little value, if we parse
the output of /proc/cpuinfo only for certain vendors.

This patch enables us to derive the correct feature flags e.g. for Qualcomm
CPUs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183790 91177308-0d34-0410-b5e6-96231b3b80d8