Changes

[nfc][libomptarget] Inline option into target_impl
Summary:
[nfc][libomptarget] Inline option into target_impl
Subset of D69423. The macros that were in option.h are all target
dependent. Inlining the header simplifies the dependency graph when
looking to move code into a common subdir.
Reviewers: ABataev, jdoerfert, grokos
Subscribers: openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D69472

[nfc][libomptarget] Decrease coupling between files
Summary:
[nfc][libomptarget] Decrease coupling between files
debug.h used the symbol omptarget_device_environment so implicitly
required an include of omptarget-nvptx.h to compile. Similarly
interface.h uses size_t.
Moving this declaration to a new header means cancel, critical can now
build without omptarget-nvptx.h. After this change, debug.h, cancel.cu,
critical.cu could move under a common source directory.
Reviewers: ABataev, jdoerfert, grokos
Subscribers: openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D69473