* target.h (init_dwarf_reg_sizes_extra): New target hook.
	* target-def.h (TARGET_INIT_DWARF_REG_SIZES_EXTRA): New default.
	* doc/tm.texi (TARGET_INIT_DWARF_REG_SIZES_EXTRA): Document.
	* dwarf2out.c (expand_builtin_init_dwarf_reg_sizes): Call this
	hook.
	* config/rs6000/rs6000.c (TARGET_INIT_DWARF_REG_SIZES_EXTRA,
	rs6000_init_dwarf_reg_sizes_extra): New.
	* config/rs6000/linux-unwind.h (ppc_fallback_frame_state): Support
	SPE register high parts.

testsuite:
	* gcc.target/powerpc/spe-unwind-1.c, g++.dg/eh/simd-5.C: New
	tests.

From-SVN: r122468