Ignore data flow info from assert calls

if assertions mode is not LEGACY.

This is done since assertions can be disabled (in both compile time and
runtime) and thus, the data flow info is not reliable anymore.
 #KT-24529: Fixed

compiler/frontend.java/src/org/jetbrains/kotlin/config/JVMAssertionsMode.kt

@@ -17,5 +17,8 @@ enum class JVMAssertionsMode(val description: String) {
 
         @JvmStatic
         fun fromStringOrNull(string: String?) = values().find { it.description == string }
+
+        @JvmStatic
+        fun fromString(string: String?) = fromStringOrNull(string) ?: DEFAULT
     }
 }