Make tests on -XXLanguage more tolerant to 1.2 -> 1.3 transition

compiler/testData/cli/jvm/internalArgWrongPrefix.out

@@ -1,5 +1,5 @@
-warning: flag is not supported by this version of the compiler: -XX:+InlineClasses
-compiler/testData/cli/jvm/inlineClass.kt:1:1: error: the feature "inline classes" is only available since language version 1.3
-inline class Foo(val x: Int)
-^
+warning: flag is not supported by this version of the compiler: -XX:+SoundSmartCastAfterTry
+compiler/testData/cli/jvm/legacySmartCastsAfterTry.kt:8:9: error: only safe (?.) or non-null asserted (!!.) calls are allowed on a nullable receiver of type String?
+    some.length
+        ^
 COMPILATION_ERROR