[GR-8748] Use @Use/@Temp instead of @Alive for modifiable variables.

[mur47x111]

No description provided.

[graalvmbot]

• It appears that user Yudi Zheng with email address yudi -(dot)- zheng -(at)- oracle -(dot)- com has not signed the Oracle Contributor Agreement.

If you believe this is an error, please contact graal-dev@openjdk.java.net.

[mur47x111]

Splitting @alive into @Use/@temp indicates that the contents could be modified, in this specific intrinsic, cnt1 and cnt2. The test case might or might not be effective depending on the machine (mine without AVX2). The goal is to make register allocator store length1 << 1 in ECX before the intrinsic, and the intrinsic has to be wrapped in a loop, see TreeMap.getEntry.