Move the closure of the subset of flang/runtime/*.h header files that
are referenced by source files outside flang/runtime (apart from unit tests)
into a new directory (flang/include/flang/Runtime) so that relative
include paths into ../runtime need not be used.
flang/runtime/pgmath.h.inc is moved to flang/include/flang/Evaluate;
it's not used by the runtime.
Differential Revision: https://reviews.llvm.org/D109107
In order for these files to build properly, this patch rolls up a number of changes that have been made to various files that have been upstreamed.
Implementations for the interfaces included in Bridge.h and IntrinsicCall.h will be included in a future diff.
Differential revision: https://reviews.llvm.org/D82608