Remove hacky re-initialization of PsiSubstitutor.KEY (branch 193)

After IDEA commit
https://github.com/JetBrains/intellij-community/commit/8b0af117241a074f5681fa93be74c6f1812497ba#diff-9b39aafa0a7b8d4f089100f3968931d0
this re-initialization is no more necessary. Moreover, it's harmful,
because this KEY is used as a map key in IDEA code,
and we cannot find information stored by this key.
This was a hidden reason of FIR / IR test failures in branch 193.

After this commit, FIR / IR tests in branch 193 should be fixed

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinCoreApplicationEnvironment.java.193

@@ -117,7 +117,6 @@ public class KotlinCoreApplicationEnvironment extends CoreApplicationEnvironment
     myApplication.registerService(EmptySubstitutor.class, emptySubstitutor);
 
     // Patch null values obtained because of cyclic dependency during initialization
-    updateInterfaceField(PsiSubstitutor.class, "KEY", KeyWithDefaultValue.create("SUBSTITUTOR", emptySubstitutor));
     updateInterfaceField(PsiSubstitutor.class, "EMPTY", emptySubstitutor);
     updateInterfaceField(PsiSubstitutor.class, "UNKNOWN", PsiSubstitutor.EMPTY);