Revert my commit in r199620 that added sections about namespaces to the
coding standards, and instead fix the existing section.

Thanks to Daniel Jasper for pointing out we already had a section
devoted to this topic. Instead of adding sections, just hack on this
section some. Also fix the example in the anonymous namespace section
below it to agree with the new advice.

As a re-cap, this switches the LLVM preferred style to never indent
namespaces. Having two approaches just led to endless (and utterly
pointless) debates about what was "small enough". This wasn't helping
anyone. The no-indent rule is easy to understand and doesn't really make
anything harder to read. Moreover, with tools like clang-format it is
considerably nicer to have simple consistent rules.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199637 91177308-0d34-0410-b5e6-96231b3b80d8
[ARM] Do not generate Tag_DIV_use=AllowDIVExt when hardware div is non-optional: it should have the default value of AllowDIVIfExists

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199638 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] llvm_process_sources: Introduce a parameter, ADDITIONAL_HEADERS.

ADDITIONAL_HEADERS is intended to add header files for IDEs as hint.

For example:
  add_llvm_library(LLVMSupport
    Host.cpp
    ADDITIONAL_HEADERS
      Unix/Host.inc
      Windows/Host.inc
    )

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199639 91177308-0d34-0410-b5e6-96231b3b80d8