The current StandardToLLVM conversion patterns only really handle
the Func dialect. The pass itself adds patterns for Arithmetic/CFToLLVM, but
those should be/will be split out in a followup. This commit focuses solely
on being an NFC rename.
Aside from the directory change, the pattern and pass creation API have been renamed:
- populateStdToLLVMFuncOpConversionPattern -> populateFuncToLLVMFuncOpConversionPattern
- populateStdToLLVMConversionPatterns -> populateFuncToLLVMConversionPatterns
- createLowerToLLVMPass -> createConvertFuncToLLVMPass