[mtouch] Look for linker input in the linker flags when parsing linker warnings.

Look for libraries passed to the linker in the linker flags, which is the
canonical location for linker input.

tools/common/CompilerFlags.cs

@@ -26,6 +26,17 @@ namespace Xamarin.Utils
 		// tracking).
 		public List<string> Inputs;
 
+		public HashSet<string> AllLibraries {
+			get {
+				var rv = new HashSet<string> ();
+				if (LinkWithLibraries != null)
+					rv.UnionWith (LinkWithLibraries);
+				if (ForceLoadLibraries != null)
+					rv.UnionWith (ForceLoadLibraries);
+				return rv;
+			}
+		}
+
 		public void ReferenceSymbol (string symbol)
 		{
 			if (UnresolvedSymbols == null)

tools/mtouch/Application.cs

@@ -1391,7 +1391,7 @@ namespace Xamarin.Bundler {
 		// this will filter/remove warnings that are not helpful (e.g. complaining about non-matching armv6-6 then armv7-6 on fat binaries)
 		// and turn the remaining of the warnings into MT5203 that MonoDevelop will be able to report as real warnings (not just logs)
 		// it will also look for symbol-not-found errors and try to provide useful error messages.
-		public static void ProcessNativeLinkerOutput (Target target, string output, IList<string> inputs, List<Exception> errors, bool error)
+		public static void ProcessNativeLinkerOutput (Target target, string output, IEnumerable<string> inputs, List<Exception> errors, bool error)
 		{
 			List<string> lines = new List<string> (output.Split (new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
 

tools/mtouch/Target.cs

@@ -951,7 +951,7 @@ namespace Xamarin.Bundler
 				var output = new StringBuilder ();
 				var code = Driver.RunCommand (App.CompilerPath, flags, null, output);
 
-				Application.ProcessNativeLinkerOutput (this, output.ToString (), link_with, linker_errors, code != 0);
+				Application.ProcessNativeLinkerOutput (this, output.ToString (), linker_flags.AllLibraries, linker_errors, code != 0);
 
 				if (code != 0) {
 					// if the build failed - it could be because of missing frameworks / libraries we identified earlier