Revert "Registry key to show hidden variables in debugger."

This reverts commit f5e6001d82.

idea/jvm-debugger/jvm-debugger-core/src/org/jetbrains/kotlin/idea/debugger/stackFrame/KotlinStackFrame.kt

@@ -12,7 +12,6 @@ import com.intellij.debugger.engine.evaluation.EvaluationContextImpl
 import com.intellij.debugger.jdi.LocalVariableProxyImpl
 import com.intellij.debugger.jdi.StackFrameProxyImpl
 import com.intellij.debugger.ui.impl.watch.*
-import com.intellij.openapi.util.registry.Registry
 import com.intellij.xdebugger.frame.XValueChildrenList
 import com.sun.jdi.*
 import org.jetbrains.kotlin.codegen.AsmUtil
@@ -176,8 +175,6 @@ class KotlinStackFrame(frame: StackFrameProxyImpl) : JavaStackFrame(StackFrameDe
 
     private fun isHidden(variable: LocalVariableProxyImpl, inlineDepth: Int): Boolean {
         val name = variable.name()
-        if (Registry.`is`("kotlin.debugger.show_hidden_vars"))
-            return false
         return isFakeLocalVariableForInline(name)
                 || name.startsWith(DESTRUCTURED_LAMBDA_ARGUMENT_VARIABLE_PREFIX)
                 || name.startsWith(AsmUtil.LOCAL_FUNCTION_VARIABLE_PREFIX)

idea/resources/META-INF/jvm.xml

@@ -189,10 +189,6 @@
                    description="Enable debugging for coroutines in Kotlin/JVM"
                    defaultValue="false"
                    restartRequired="false"/>
-        <registryKey key="kotlin.debugger.show_hidden_vars"
-                     description="Show hidden variables Kotlin/JVM"
-                     defaultValue="false"
-                     restartRequired="false"/>
     </extensions>
 
     <extensions defaultExtensionNs="org.jetbrains.uast">