Generate not-null assertions after method calls

If a method comes from Java and is annotated as returning NotNull, after
calling it we should check if it actually returned something other than null.
Introduce checkReturnedValueIsNotNull() in jet/runtime/Intrinsics which does
exactly that.

CallableMethod's invoke() and invokeDefault() are now private, use asserted
versions instead

compiler/android-tests/tests/org/jetbrains/jet/compiler/android/SpecialFiles.java

@@ -126,6 +126,9 @@ public class SpecialFiles {
         excludedFiles.add("kt529.kt");  // Bug
 
         excludedFiles.add("noClassObjectForJavaClass.kt");
+
+        excludedFiles.add("doGenerateAssertions.kt"); // Multi-file + Java
+        excludedFiles.add("doNotGenerateAssertions.kt"); // Multi-file + Java
     }
 
     private SpecialFiles() {