Hello

OpenMP 5.0 has a new feature for implicitly marking variables and functions that 
are referenced in the initializers of static variables and functions that are 
already marked 'declare target'. Support was added in the commit 'openmp: 
Implement discovery of implicit declare target to clauses' 
(dc703151d4f4560e647649506d5b4ceb0ee11e90). However, this does not work with 
non-constant C++ initializers, where the initializers can contain references to 
other (non-constant) variables and function calls.

The C++ front-end stores the initialization information in the static_aggregates 
list (with the variable decl in the TREE_VALUE of an entry and the 
initialization in TREE_PURPOSE) rather than in TREE_INITIAL(var_decl). I have 
added an extra function in omp-offload.cpp to walk the variable initialiser 
trees in static_aggregates, and added a call to it from the FE shortly before 
the initializations are emitted. I have also added a testcase to ensure that the 
implicitly marked variables/functions can be referenced in offloaded code.

The libgomp tests have been run with offloading to a Nvidia card with no 
regressions, and I have also bootstrapped the compiler with no offloading on 
x86-64. Okay for trunk?

Thanks

Kwok