VM args ignored on Windows when set via launchIde constructor

[daveames]

When launching the IDE for robot tests using launchIde the VM args aren't set on the IDE.

The launcher sets the VM options using a file set in by a enviroment variable, IDEA_VM_OPTIONS (see https://www.jetbrains.com/help/idea/tuning-the-ide.html#configure-jvm-options).

On Windows this variable isn't set, instead a IDEA64_VM_OPTIONS is set on windows,

intellij-ui-test-robot/ide-launcher/src/main/kotlin/com/intellij/remoterobot/launcher/Ide.kt

Line 31 in ff1d138

val productPrefix = it.substringBefore("_")

(https://github.com/JetBrains/intellij-ui-test-robot/blame/ff1d138be8155bc9b1fba9a321646f655ae42aaa/ide-launcher/src/main/kotlin/com/intellij/remoterobot/launcher/Ide.kt#L32). This file looks to never be read by the IDE.

I have tested running IntelliJ with IDEA_VM_OPTIONS and then tried with IDEA64_VM_OPTIONS set. When IDEA64_VM_OPTIONS is set my VM args are ignored. When IDEA_VM_OPTIONS is set the VM args are set.