Handle casesi dispatch tablejumps in create_trace_edges (as well)

Handle casesi dispatch tablejumps in create_trace_edges (as well)

	* rtlanal.c (tablejump_casesi_pattern): New function, to
	determine if a tablejump insn is a casesi dispatcher. Extracted
	from patch_jump_insn.
	* rtl.h (tablejump_casesi_pattern): Declare.
	* cfgrtl.c (patch_jump_insn): Use it.
	* dwarf2cfi.c (create_trace_edges): Use it.

testsuite/

	* gnat.dg/casesi.ad[bs], test_casesi.adb: New test.

From-SVN: r274377