Renamed -Xklib-mpp to -Xexpect-actual-linker to reduce user confusion

compiler/testData/cli/js/jsExtraHelp.out

@@ -32,13 +32,13 @@ where advanced options include:
   -Xdump-fqname              FqName of declaration that should be dumped
   -Xdump-perf=<path>         Dump detailed performance statistics to the specified file
   -Xeffect-system            Enable experimental language feature: effect system
+  -Xexpect-actual-linker     Enable experimental expect/actual linker
   -Xexperimental=<fq.name>   Enable and propagate usages of experimental API for marker annotation with the given fully qualified name
   -Xexplicit-api={strict|warning|disable}
                              Force compiler to report errors on all public API declarations without explicit visibility or return type.
                              Use 'warning' level to issue warnings instead of errors.
   -Xinline-classes           Enable experimental inline classes
   -Xintellij-plugin-root=<path> Path to the kotlin-compiler.jar or directory where IntelliJ configuration files can be found
-  -Xklib-mpp                 Enable experimental support for multi-platform klib libraries
   -Xlegacy-smart-cast-after-try Allow var smart casts despite assignment in try block
   -Xlist-phases              List backend phases
   -Xmetadata-version         Change metadata version of the generated binary files