FE: Fix null assertion error when left is CollectionLiteral

#KT-49961 fixed

compiler/testData/diagnostics/tests/inference/kt49961.fir.kt

@@ -0,0 +1,10 @@
+class Xyz {
+    fun x(): String? {
+        return try {
+            <!UNSUPPORTED!>[<!UNRESOLVED_REFERENCE!>a<!>]<!> <!USELESS_ELVIS!>?: <!UNRESOLVED_REFERENCE!>XYZ<!><!>
+        }
+        catch (e: Exception) {
+            null
+        }
+    }
+}

compiler/testData/diagnostics/tests/inference/kt49961.kt

@@ -0,0 +1,10 @@
+class Xyz {
+    fun x(): String? {
+        return try {
+            <!TYPE_MISMATCH, UNSUPPORTED!>[<!UNRESOLVED_REFERENCE!>a<!>]<!> <!USELESS_ELVIS!>?: <!UNRESOLVED_REFERENCE!>XYZ<!><!>
+        }
+        catch (e: Exception) {
+            null
+        }
+    }
+}

compiler/testData/diagnostics/tests/inference/kt49961.txt

@@ -0,0 +1,9 @@
+package
+
+public final class Xyz {
+    public constructor Xyz()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public final fun x(): kotlin.String?
+}