[Gradle, native] Make tests tolerate to stacktrace format changes

The K/N compiler changed the way in which inline functions are shown
in stacktraces. When an exception is thrown from an inline function,
the stacktrace refers to a line in the body of the inline function
while in 1.3.7x it referred to a line when the inline function is called.

This patch gets rid of inline functions in the corresponding test
to make it independent on such changes in the stacktrace format.

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/NewMultiplatformIT.kt

@@ -1605,7 +1605,7 @@ class NewMultiplatformIT : BaseGradleIT() {
             """
                 @Test
                 fun fail() {
-                    error("FAILURE!")
+                    throw IllegalStateException("FAILURE!")
                 }
             """.trimIndent()
         )