RFR: JDK-8251193 bin/idea.sh generating wrong source folders for JVMCI modules

[Galder Zamarreno]

Hi,

`bin/idea.sh` is not generating the right source folders for
jdk.internal.vm.ci and jdk.internal.vm.compiler modules.

These modules have different directory structures to the rest and so should
be handled exceptionally so that the IDE has the right source folder
definitions.

The fix takes these two modules, inspects all the subdirectories within
each module root and generates a source folder definition for each. As
example, for jdk.internal.vm.ci, there should be a source folder for:

* src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.aarch64/src
* src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.amd64/src
* ...

I've tested this in the patch on IDEA 2020.2.

Bug: https://bugs.openjdk.java.net/browse/JDK-8251193
WebRev:
http://cr.openjdk.java.net/~sgehwolf/webrevs/galder/JDK-8251193/01/webrev/

Galder