CMake properly detects the toolkit directories as implicit system
includes, but CUDA compilers don't add explicit `-isystem` markups to
these directories when compiling CUDA code. Due to this limitation,
allow users to explicitly specify these directories as SYSTEM dirs.
Fixes: #16464, #19864
Fixes#17559
Replace our hard-coded default of cudart=static with a first-class abstraction to select the runtime library from an enumeration of logical names.
When we report that a compiler was unable to build a simple test
program, indent the output of the attempt so that our message formatting
will show it as a pre-formatted block.
