meson: Split out tcg/meson.build

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/meson.build

@@ -0,0 +1,13 @@
+tcg_ss = ss.source_set()
+
+tcg_ss.add(files(
+  'optimize.c',
+  'tcg.c',
+  'tcg-common.c',
+  'tcg-op.c',
+  'tcg-op-gvec.c',
+  'tcg-op-vec.c',
+))
+tcg_ss.add(when: 'CONFIG_TCG_INTERPRETER', if_true: files('tci.c'))
+
+specific_ss.add_all(when: 'CONFIG_TCG', if_true: tcg_ss)