Enable syntax-only support for generic functions by default.

pkg/compiler/lib/src/options.dart

Index: pkg/compiler/lib/src/options.dart
diff --git a/pkg/compiler/lib/src/options.dart b/pkg/compiler/lib/src/options.dart
index 65ea1b809498d2cfa8be8221ebac6ee7a77dfb06..f490329e7afc9997f9053e0fb59fd02d6bfb6d75 100644
--- a/pkg/compiler/lib/src/options.dart
+++ b/pkg/compiler/lib/src/options.dart
@@ -289,7 +289,7 @@ class CompilerOptions implements DiagnosticOptions, ParserOptions {
         dumpInfo: _hasOption(options, Flags.dumpInfo),
         enableAssertMessage: _hasOption(options, Flags.enableAssertMessage),
         enableGenericMethodSyntax:
-            _hasOption(options, Flags.genericMethodSyntax),
+            true, // No check for `Flags.genericMethodSyntax`: always enabled.

[Siggi Cherem (dart-lang), 2016/11/10 20:54:50]

suggestion: consider deleting this property from here and ParserOptions
altogether. I'd be OK doing that on a separate CL, but I'm also happy to do it
at once. Note: we will still accept the flag on the command line with the rest
of your changes as you have them (since it's still listed in
command_options.dart). This will just simplify the API internally within the
compiler.

         enableInitializingFormalAccess:
             _hasOption(options, Flags.initializingFormalAccess),
         enableExperimentalMirrors: