build-system: clean up TCG/TCI configury

Make CONFIG_TCG_INTERPRETER a Meson option, and enable TCI (though with
a warning) if the host CPU is unsupported, making it more similar to
other --enable-* options.

Remove TCG-specific include paths from !CONFIG_TCG builds.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/configure b/configure
index f16fa99..a84df7c 100755
--- a/configure
+++ b/configure
@@ -359,7 +359,7 @@
 tsan="no"
 fortify_source="$default_feature"
 strip_opt="yes"
-tcg_interpreter="no"
+tcg_interpreter="false"
 bigendian="no"
 mingw32="no"
 gcov="no"
@@ -1119,9 +1119,9 @@
   ;;
   --enable-whpx) whpx="enabled"
   ;;
-  --disable-tcg-interpreter) tcg_interpreter="no"
+  --disable-tcg-interpreter) tcg_interpreter="true"
   ;;
-  --enable-tcg-interpreter) tcg_interpreter="yes"
+  --enable-tcg-interpreter) tcg_interpreter="false"
   ;;
   --disable-cap-ng)  cap_ng="disabled"
   ;;
@@ -5834,11 +5834,6 @@
 if test "$optreset" = "yes" ; then
   echo "HAVE_OPTRESET=y" >> $config_host_mak
 fi
-if test "$tcg" = "enabled"; then
-  if test "$tcg_interpreter" = "yes" ; then
-    echo "CONFIG_TCG_INTERPRETER=y" >> $config_host_mak
-  fi
-fi
 if test "$fdatasync" = "yes" ; then
   echo "CONFIG_FDATASYNC=y" >> $config_host_mak
 fi