Make pdbdump-objfilename test work again

- The test had extension .yaml, which lit doesn't execute in this
  directory. Rename to .test to make it run, and move the yaml bits
  into a dedicated file, like with all other tests in this dir.

- llvm-pdbdump got renamed to llvm-pdbutil long ago, update test.

- -dbi-module-info got renamed in r305032, update test for this too.

llvm-svn: 365514