target/sparc: Drop use of gen_io_end()

target/sparc: Drop use of gen_io_end()

The gen_io_end() function is obsolete (as documented in
docs/devel/tcg-icount.rst). Where an instruction is an I/O
operation, the translator frontend should call gen_io_start()
before generating the code which does the I/O, and then
end the TB immediately after this insn.

Remove the calls to gen_io_end() in the SPARC frontend,
and ensure that the insns which were calling it end the
TB if they didn't do so already.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210724134902.7785-2-peter.maydell@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>