TCG: Fix tcg_gen_extr_i64_tl for 32bit

We expose a generic helper "tcg_gen_extr_i64_tl" for 64bit targets, but the
same function for 32bit targets is a misnomer and refers to an invalid function
name.

Fix up the definition to point to the correct internal helper names instead.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: e500: Merge 32 and 64 bit SPE emulation

Today we have a lot of conditional code in the SPE emulation depending on
whether we have 64bit GPRs or not.

Unfortunately the assumption that we can just recycle the 64bit GPR
implementation is wrong. Normal SPE implementations maintain the upper 32 bits
on all non-SPE instructions which then only modify the low 32 bits. However
all instructions we model that adhere to the normal SF based switching don't
care whether they operate on 32 or 64 bit registers and just always use the full
64 bits.

So let's remove that dubious SPE optimization and revert everything to the same
code path the 32bit target code was taking. That way we get rid of differences
between the two implementations, but will get a slight performance hit when
emulating SPE instructions.

This fixes SPE emulation with qemu-system-ppc64 for me.

Signed-off-by: Alexander Graf <agraf@suse.de>