target/ppc: move opcode decode tables to PowerPCCPU

target/ppc: move opcode decode tables to PowerPCCPU

The opcode decode tables aren't really part of the CPUPPCState but an
internal implementation detail for the translator. This can cause
problems with memcpy in cpu_copy as any table created during
ppc_cpu_realize get written over causing a memory leak. To avoid this
move the tables into PowerPCCPU which is better suited to hold
internal implementation details.

Attempts to fix: https://bugs.launchpad.net/qemu/+bug/1836558
Cc: 1836558@bugs.launchpad.net
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20190716121352.302-1-alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>