1. Jtreg tests for VectorMask query (trueCount, firstTrue, lastTrue) is not effective. The tests failure cannot be reported.
     The main reason is that the methods are not hot enough to be compiled by C2 compiler.

Besides, after fixing the jtreg issue, the JVM crashes with the following assertion failure:

# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc: SuppressErrorAt=/vectornode.hpp:879
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/home/xiagon01/code/panama-vector/src/hotspot/share/opto/vectornode.hpp:879), pid=168241, tid=168257
# Error: assert(mask->Opcode() == Op_VectorStoreMask) failed
#
# JRE version: OpenJDK Runtime Environment (18.0) (fastdebug build 18-internal+0-git-d353bd9398)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 18-internal+0-git-d353bd9398, mixed mode, sharing, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# V [libjvm.so+0x1833be4] VectorMaskOpNode::make(Node*, Type const*, int)+0x19c
The input of the mask might be "LoadVector", since there is the optimization:

VectorStoreMask (VectorLoadMask value) ==> value