[clang] [HLSL] Move `_init_resource_bindings` to entry point functions (PR #119311)

[Chris B via cfe-commits]

llvm-beanz wrote:

Is this the right solution, or should we be doing something to force the constructor function to be generated. I'm a little worried that we have one path for initializing some types of globals and a different approach for other globals.

https://github.com/llvm/llvm-project/pull/119311