[flang] CUDA Fortran - part 4/5: definability and characteristics

Extend the definability and procedure characteristics checking
infrastructure in semantics to check for context-dependent CUDA object
definability violations and problems with CUDA attribute incompatibility
in procedure interfaces.

Depends on https://reviews.llvm.org/D150159,
https://reviews.llvm.org/D150161, & https://reviews.llvm.org/D150162.

Differential Revision: https://reviews.llvm.org/D150163