tcg-i386: Tidy calls. Define OPC_CALL_Jz, generated by tcg_out_calli; use the later throughout. Unify the calls within qemu_st; adjust the stack with a single pop if applicable. Define and use EXT_CALLN_Ev for indirect calls. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>