command line script launcher

% ./bin/kotlin -script hello.ktscript
hello world

% cat hello.ktscript
fun hello(what: String) = println("hello $what")
hello("world")

Note it currently takes 8 seconds to evaluate hello world script.

compiler/integration-tests/data/help/help.expected

@@ -8,6 +8,7 @@ OUT   -altHeaders [String] Path to the alternative library headers paths
 OUT   -mode [String] Special compiler modes: stubs or altHeaders
 OUT   -output [String] output directory
 OUT   -module [String] module to compile
+OUT   -script [flag]
 OUT   -tags [flag]
 OUT   -verbose [flag]
 OUT   -version [flag]