[llvm] [llvm-pdbutil] Create public symbols in yaml2pdb (PR #157362)

[Alexandre Ganea via llvm-commits]

================
@@ -0,0 +1,22 @@
+---
----------------
aganea wrote:

This file is small enough that you can merge it in the contents of the test below. You can then do `# RUN: llvm-pdbutil yaml2pdb %s --pdb=%t.pdb` (dash, not semicolon for starting lines, as it should be a valid yaml). Take a look at `pdb-invalid-type.test` for an example.

https://github.com/llvm/llvm-project/pull/157362