Use java.lang.Object as a fall-back reference type

If for some reason during preliminary analysis in redundant null check
elimination we failed to determine a local variable type statically,
treat it as java.lang.Object.
This will disable some further optimizations using precise type
information (such as INSTANCEOF check elimination), but will not fail
with an exception anyway.

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/nullCheck/RedundantNullCheckMethodTransformer.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.codegen.optimization.common.isInsn
 import org.jetbrains.kotlin.codegen.optimization.fixStack.peek
 import org.jetbrains.kotlin.codegen.optimization.fixStack.top
 import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
+import org.jetbrains.kotlin.resolve.jvm.AsmTypes
 import org.jetbrains.kotlin.utils.SmartList
 import org.jetbrains.org.objectweb.asm.Label
 import org.jetbrains.org.objectweb.asm.Opcodes
@@ -42,9 +43,6 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
     private class TransformerPass(val internalClassName: String, val methodNode: MethodNode) {
         private var changes = false
 
-        private fun AbstractInsnNode.getIndex() =
-                methodNode.instructions.indexOf(this)
-
         fun run(): Boolean {
             val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode()
             eliminateRedundantChecks(checkedReferenceTypes)
@@ -236,7 +234,7 @@ class RedundantNullCheckMethodTransformer : MethodTransformer() {
                 for ((varIndex, dependentChecks) in checksDependingOnVariable) {
                     for (checkInsn in dependentChecks) {
                         val varType = checkedReferenceTypes[checkInsn]
-                                      ?: throw AssertionError("No var type @${checkInsn.getIndex()}")
+                                      ?: AsmTypes.OBJECT_TYPE
                         nullabilityAssumptions.injectAssumptionsForCheck(varIndex, checkInsn, varType)
                     }
                 }