This allows-fembed-offload-object's and -fopenmp-is-device
compiler invocation arguments to be passed to the Flang frontend
during split compilation when offloading in OpenMP.
An example use case is when passing an offload-arch alongside
-fopenmp to embed device objects compiled for the offload-arch
within the host architecture.
This borrows from existing clangDriver+Clang.h/.cpp work and the intent is
currently to reuse as much of the existing infrastructure and design as we can to
achieve offloading for Flang+OpenMP. An overview of Clang's offloading design
can be found here: https://clang.llvm.org/docs/OffloadingDesign.html
What's the magic "1"? And given that the input count matters here - is there a test with multiple inputs?