[PowerAssert] Reproduce KT-66208

plugins/power-assert/testData/codegen/operator/ExcleqeqOperator.kt

@@ -0,0 +1,21 @@
+fun box() = expectThrowableMessage {
+    assert(1 !== 1)
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't just search for `!==` in the expression.
+    assert(" !== " !== " !== ")
+} + "\n\n" + expectThrowableMessage {
+    // Test multiline case
+    assert(
+        " !== "
+
+                !==
+
+                " !== "
+    )
+} + "\n\n" + expectThrowableMessage {
+    // Test that we don't assume whitespaces around the infix operator
+    assert(1/*!==*/!==/*!==*/1)
+} + "\n\n" + expectThrowableMessage {
+    // Test nested `!==`
+    assert((1 !== 1) !== false)
+}