Add asserts for diagnosing Windows test failure

Change-Id: Id7635065e3b9d6f09dadde66cca568022c82e36f

src/test/java/com/android/tools/r8/shaking/ProguardConfigurationParserTest.java

diff --git a/src/test/java/com/android/tools/r8/shaking/ProguardConfigurationParserTest.java b/src/test/java/com/android/tools/r8/shaking/ProguardConfigurationParserTest.java
index 5d80257..1ab4943 100644
--- a/src/test/java/com/android/tools/r8/shaking/ProguardConfigurationParserTest.java
+++ b/src/test/java/com/android/tools/r8/shaking/ProguardConfigurationParserTest.java
@@ -22,6 +22,7 @@
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import com.android.tools.r8.Diagnostic;
 import com.android.tools.r8.TestBase;
 import com.android.tools.r8.TestParameters;
 import com.android.tools.r8.TestParametersCollection;
@@ -34,6 +35,7 @@
 import com.android.tools.r8.graph.FieldAccessFlags;
 import com.android.tools.r8.graph.MethodAccessFlags;
 import com.android.tools.r8.position.Position;
+import com.android.tools.r8.position.TextPosition;
 import com.android.tools.r8.position.TextRange;
 import com.android.tools.r8.shaking.ProguardClassNameList.SingleClassNameList;
 import com.android.tools.r8.shaking.ProguardConfiguration.ProcessKotlinNullChecks;
@@ -3383,6 +3385,15 @@
     } catch (RuntimeException e) {
       assertTrue(e.getCause() instanceof AbortException);
       assertEquals(1, handler.errors.size());
+      Diagnostic error = handler.errors.get(0);
+      assertTrue(error instanceof ProguardRuleParserErrorDiagnostic);
+      assertTrue(error.getPosition() instanceof TextPosition);
+      TextPosition position = (TextPosition) error.getPosition();
+      assertEquals(1, position.getLine());
+      assertEquals(48, position.getColumn());
+      assertThat(
+          error.getDiagnosticMessage(),
+          containsString("Unexpected line termination in string literal"));
       assertThat(
           handler.errors.get(0),
           allOf(