JetDiagnosticsTest migrated to TestGenerator

- test data files renamed from *.jet to *.kt

compiler/testData/diagnostics/tests/controlFlowAnalysis/kt2166_kt2103.kt

@@ -0,0 +1,17 @@
+package a
+
+//KT-2166 Control flow analysis doesn't detect that a 'while(true)' loop never terminates
+fun foo(): Int {
+    while (true) {
+    }
+}
+
+//KT-2103 Compiler requires return statement after loop which never exits
+fun foo1() : Boolean{
+    while(true){
+        if (bar()) continue
+        return true
+    }
+}
+
+fun bar() : Boolean = true