Use a reference instead of making an unnecessary copy. Also use 'const'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188483 91177308-0d34-0410-b5e6-96231b3b80d8
Make a few more things const.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188484 91177308-0d34-0410-b5e6-96231b3b80d8
make arm-reserve-r9 available for all ARM

r9 is defined as a platform-specific register in the ARM EABI.
It can be reserved for a special purpose or be used as a general
purpose register. Add support for reserving r9 for all ARM, while
leaving the IOS usage unchanged.

Patch by Jeroen Hofstee.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188485 91177308-0d34-0410-b5e6-96231b3b80d8
make arm-use-movt available for all ARM

Before this patch this flag is IOS specific, but is also
useful for bare project like bootloaders / kernels etc,
since movw / movt prevents simple relocation. Therefore
make this flag more commonly available.

note: this patch depends on a similiar rename in clang

Patch by Jeroen Hofstee.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188487 91177308-0d34-0410-b5e6-96231b3b80d8