Currently, APX is not enabled consistently between product and debug builds.

If the hardware supports Intel APX:
1) In fastdebug and debug builds, APX is enabled by default if the underlying hardware supports Intel APX feature.
2) In product builds, APX is disabled by default and the user cannot also explicitly enable it using -XX:+UnlockExperimentalVMOptions -XX:+UseAPX.

The proposal is to make the behavior consistent i.e., disable UseAPX by default for all builds and enable it for all builds if and only if the user explicitly specifies -XX:+UnlockExperimentalVMOptions -XX:+UseAPX on the command line.