target/mips: Add declarations for generic TCG helpers

target/mips: Add declarations for generic TCG helpers

We want to extract the microMIPS ISA and Code Compaction ASE to
new compilation units.

We will first extract this code as included source files (.c.inc),
then make them new compilation units afterward.

The following methods are going to be used externally:

  micromips_translate.c.inc:1778:   gen_ldxs(ctx, rs, rt, rd);
  micromips_translate.c.inc:1806:   gen_align(ctx, 32, rd, rs, ...
  micromips_translate.c.inc:2859:   gen_addiupc(ctx, reg, offset, ...
  mips16e_translate.c.inc:444:      gen_addiupc(ctx, ry, offset, ...

To avoid too much code churn, it is simpler to declare these
prototypes in "translate.h" now.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210617174907.2904067-2-f4bug@amsat.org>