The following program results in an ICE with pgfortran 18.10.
use, intrinsic :: iso_c_binding
integer, target :: x
print *, c_associated(c_loc(x))
end
Lowering Error: unknown operator for LHS or argument [ast=0,asttype=0,datatype=0]
Lowering Error: unexpected data type at load [ast=0,asttype=0,datatype=0]
PGF90-F-0000-Internal compiler error. Errors in Lowering 2 (mysource.f90: 8)
PGF90/x86-64 Linux 18.10-0: compilation aborted
x as a pointer (with or without initial target) also results in an ICE.