This is a follow-up to https://reviews.llvm.org/D140896, split into several parts as it touches a lot of files. Differential Revision: https://reviews.llvm.org/D141298
This change introduces C API helper functions to work with PDL types. Modification closely follow the format of the https://reviews.llvm.org/D116546. Reviewed By: ftynse Differential Revision: https://reviews.llvm.org/D117221
Reviewed By: nicolasvasilache Differential Revision: https://reviews.llvm.org/D116546