Teach index working with source roots with package prefix

#KT-9167 Fixed

jps-plugin/testData/general/SourcePackageLongPrefix/module1/module1.iml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" packagePrefix="good.prefix" />
+    </content>
+    <orderEntry type="jdk" jdkName="IDEA_JDK" jdkType="JavaSDK" />
+    <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="library" name="KotlinRuntime" level="project" />
+  </component>
+</module>
+

jps-plugin/testData/general/SourcePackageLongPrefix/module1/src/JavaDependency.java

@@ -0,0 +1,6 @@
+package good.prefix;
+
+public class JavaDependency {
+    public void bar() {}
+}
+

jps-plugin/testData/general/SourcePackageLongPrefix/module1/src/JavaTest.java

@@ -0,0 +1,6 @@
+package good.prefix;
+
+public class JavaTest extends JavaDependency {
+    
+}
+

jps-plugin/testData/general/SourcePackageLongPrefix/module1/src/inBadPrefix.kt

@@ -0,0 +1,4 @@
+package bad.prefix
+
+class KotlinTestInBadPrefix
+

jps-plugin/testData/general/SourcePackageLongPrefix/module1/src/isGoodPrefix.kt

@@ -0,0 +1,3 @@
+package good.prefix
+
+class KotlinTestInGoodPrefix

jps-plugin/testData/general/SourcePackageLongPrefix/module1/src/test/other/otherTest.kt

@@ -0,0 +1,9 @@
+package test.other
+
+import bad.prefix.KotlinTestInBadPrefix
+import good.prefix.KotlinTestInGoodPrefix
+import good.prefix.JavaTest;
+
+val goodTest = KotlinTestInGoodPrefix()
+val badTest = KotlinTestInBadPrefix()
+val javaTest = JavaTest().bar()