Vector element extraction without stack operations on Power 8
This patch corresponds to review:
This patch builds onto the patch that provided scalar to vector conversions
without stack operations (D11471).
Included in this patch:
- Vector element extraction for all vector types with constant element number
- Vector element extraction for v16i8 and v8i16 with variable element number
- Removal of some unnecessary COPY_TO_REGCLASS operations that ended up unnecessarily moving things around between registers
Not included in this patch (will be in upcoming patch):
- Vector element extraction for v4i32, v4f32, v2i64 and v2f64 with variable element number
- Vector element insertion for variable/constant element number
Testing is provided for all extractions. The extractions that are not
implemented yet are just placeholders.