ipa/106124 - ICE with -fkeep-inline-functions and OpenMP

ipa/106124 - ICE with -fkeep-inline-functions and OpenMP

The testcases in this bug reveal cases where an early generated
type is collected because it was unused but gets attempted to
be recreated later when a late DIE for a function (an OpenMP
reduction) is created.  That's unexpected and possibly the fault
of OpenMP but the following allows the re-creation of the context
type to succeed.

	PR ipa/106124
	* dwarf2out.cc (lookup_type_die): Reset TREE_ASM_WRITTEN
	so we can re-create the DIE for the type if required.

	* g++.dg/gomp/pr106124.C: New testcase.