Fix DexFile's line number and test EH and StackTraceElement in 3 ways.

Testing exception handling: 1. Walking stack 10 levels and then check
depth == 10. 2. Check if correct stack trace is being generated. 3. For
native frame, lineno should be -2 to indicate it is native. Note that
"line number == -2" is how libcore tells from StackTraceElement.

Change-Id: If38c16a59624f259985bcfcebc337b73b0582460
diff --git a/src/exception_test.cc b/src/exception_test.cc
index 259c0a4..cc5e3e0 100644
--- a/src/exception_test.cc
+++ b/src/exception_test.cc
@@ -157,17 +157,14 @@
                trace_array->Get(0)->GetDeclaringClass()->ToModifiedUtf8().c_str());
   EXPECT_STREQ("MyClass.java", trace_array->Get(0)->GetFileName()->ToModifiedUtf8().c_str());
   EXPECT_STREQ("g", trace_array->Get(0)->GetMethodName()->ToModifiedUtf8().c_str());
-  EXPECT_EQ(22u, trace_array->Get(0)->GetLineNumber());
+  EXPECT_EQ(22, trace_array->Get(0)->GetLineNumber());
 
   ASSERT_TRUE(trace_array->Get(1) != NULL);
   EXPECT_STREQ("java.lang.MyClass",
                trace_array->Get(1)->GetDeclaringClass()->ToModifiedUtf8().c_str());
   EXPECT_STREQ("MyClass.java", trace_array->Get(1)->GetFileName()->ToModifiedUtf8().c_str());
   EXPECT_STREQ("f", trace_array->Get(1)->GetMethodName()->ToModifiedUtf8().c_str());
-  EXPECT_EQ(7u, trace_array->Get(1)->GetLineNumber());
+  EXPECT_EQ(7, trace_array->Get(1)->GetLineNumber());
 }
 
-// TODO: Test with native frame: For native frame, lineno should be -2 to
-// indicate it is native. That is how libcore tells from the StackTraceElement.
-
 }  // namespace art