JVMTI NotifyFramePop support

Adds support for the JVMTI can_generate_frame_pop_events capability.
This includes the NotifyFramePop function and the FramePop event.

We mark the interpreter shadowframes directly to get the events. This
relies on the fact that we never replace extant shadow-frames on the
interpreter stack to ensure that we can distinguish which jvmti-envs
requested the frame pops.

Test: ./test.py --host -j50
Bug: 34414072
Bug: 62821960
Bug: 65129403

Change-Id: I6e79e39f62fdf79268540c5c1be6311df704cff7
diff --git a/test/1923-frame-pop/src/art/StackTrace.java b/test/1923-frame-pop/src/art/StackTrace.java
new file mode 100644
index 0000000..2ea2f20
--- /dev/null
+++ b/test/1923-frame-pop/src/art/StackTrace.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package art;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Executable;
+
+public class StackTrace {
+  public static class StackFrameData {
+    public final Thread thr;
+    public final Executable method;
+    public final long current_location;
+    public final int depth;
+
+    public StackFrameData(Thread thr, Executable e, long loc, int depth) {
+      this.thr = thr;
+      this.method = e;
+      this.current_location = loc;
+      this.depth = depth;
+    }
+    @Override
+    public String toString() {
+      return String.format(
+          "StackFrameData { thr: '%s', method: '%s', loc: %d, depth: %d }",
+          this.thr,
+          this.method,
+          this.current_location,
+          this.depth);
+    }
+  }
+
+  public static native int GetStackDepth(Thread thr);
+
+  private static native StackFrameData[] nativeGetStackTrace(Thread thr);
+
+  public static StackFrameData[] GetStackTrace(Thread thr) {
+    // The RI seems to give inconsistent (and sometimes nonsensical) results if the thread is not
+    // suspended. The spec says that not being suspended is fine but since we want this to be
+    // consistent we will suspend for the RI.
+    boolean suspend_thread =
+        !System.getProperty("java.vm.name").equals("Dalvik") &&
+        !thr.equals(Thread.currentThread()) &&
+        !Suspension.isSuspended(thr);
+    if (suspend_thread) {
+      Suspension.suspend(thr);
+    }
+    StackFrameData[] out = nativeGetStackTrace(thr);
+    if (suspend_thread) {
+      Suspension.resume(thr);
+    }
+    return out;
+  }
+}
+