target/mips: Extract MXU code to new mxu_translate.c file

Extract 1600+ lines from the big translate.c into a new file.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210226093111.3865906-14-f4bug@amsat.org>

target/mips/meson.build

@@ -24,6 +24,10 @@ mips_tcg_ss.add(files(
   'translate.c',
   'translate_addr_const.c',
 ))
+mips_tcg_ss.add(when: 'TARGET_MIPS64', if_false: files(
+  'mxu_translate.c',
+))
+
 mips_ss.add(when: 'CONFIG_KVM', if_true: files('kvm.c'))
 
 mips_softmmu_ss = ss.source_set()