RFR: 8261846: [JVMCI] c2v_iterateFrames can get out of sync with the StackFrameStream

[Dean Long]

On Wed, 17 Feb 2021 00:46:12 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

>> c2v_iterateFrames mixes a StackFrameSteam and vframes and the vframe factory method can silently skip stub frames. The could leave the StackFrameStream out of sync with the vframe walk. This can cause the iteration fail in strange ways and assert in fastdebug builds.
>
> Update copyright year in vframe.hpp.
> Otherwise good.

Hi Tom.  This code could be simplified and made faster using vframeStream as the iterator and vframeStream:asJavaVFrame to get the vframe.  If you don't need the locals of every frame, then vframeStream::next is faster than vframe::sender.  See JDK-8214329.

-------------

PR: https://git.openjdk.java.net/jdk/pull/2594