[ARM] Replace development diagnostics with normal DEBUG macro

* Remove the -arm-asm-parser-dev-diags option.
* Use normal DEBUG(dbgs()) printing for the extra development information about
  missing diagnostics.

Differential Revision: https://reviews.llvm.org/D39194



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316423 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed