Add -e flag for new driver (#61171)

Matches swiftlang/swift-driver#1188.

Author: beccadax

include/swift/Option/Options.td

@@ -241,6 +241,9 @@ def tools_directory : Separate<["-"], "tools-directory">,
 
 def D : JoinedOrSeparate<["-"], "D">, Flags<[FrontendOption]>,
   HelpText<"Marks a conditional compilation flag as true">;
+  
+def e : JoinedOrSeparate<["-"], "e">, Flags<[NewDriverOnlyOption]>,
+  HelpText<"Executes a line of code provided on the command line">;
 
 def F : JoinedOrSeparate<["-"], "F">,
   Flags<[FrontendOption, ArgumentIsPath, SwiftAPIExtractOption, SwiftSymbolGraphExtractOption, SwiftAPIDigesterOption]>,