Prepare the configuration parameters needed for implementing a new runtime calling convention.
Prepare the configuration parameters needed for implementing a new runtime calling convention.

Define a number of macro definitions that will be used for:
- proper auto-generation of LLVM IR level declarations of runtime function using RuntimeFunctions.def
- generation of wrappers for runtime functions
- setting proper calling conventions, visibility and other attributes of runtime functions inside the runtime library.

khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift,khizkhiz/swift