tree-optimization/106938 - cleanup abnormal edges after inlining

After inlining and IPA transforms we run fixup_cfg to fixup CFG
effects in other functions.  But that fails to clean abnormal
edges from non-pure/const calls which might no longer be necessary
when ->calls_setjmp is false.  The following ensures this happens
and refactors things so we call EH/abnormal cleanup only on the
last stmt in a block.

	PR tree-optimization/106938
	* tree-cfg.cc (execute_fixup_cfg): Purge dead abnormal
	edges for all last stmts in a block.  Do EH cleanup
	only on the last stmt in a block.

	* gcc.dg/pr106938.c: New testcase.