KT-5425 Kotlin plugin crashes when project uses RxJava 17.0 or older

#KT-5425 Fixed

compiler/testData/diagnostics/tests/j+k/samInConstructorWithGenerics.kt

@@ -0,0 +1,21 @@
+// FILE: j/OnSubscribe.java
+package j;
+
+public interface OnSubscribe<T> {
+    void f();
+}
+
+// FILE: j/Observable.java
+package j;
+
+public class Observable<T> {
+
+    protected Observable(OnSubscribe<T> f) {
+    }
+}
+
+// FILE: Kotlin.kt
+
+import j.*
+
+class K : Observable<String>({})

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -5151,6 +5151,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest("compiler/testData/diagnostics/tests/j+k/recursiveRawUpperBound.kt");
             }
             
+            @TestMetadata("samInConstructorWithGenerics.kt")
+            public void testSamInConstructorWithGenerics() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/j+k/samInConstructorWithGenerics.kt");
+            }
+            
             @TestMetadata("Simple.kt")
             public void testSimple() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/j+k/Simple.kt");

core/descriptor.loader.java/src/org/jetbrains/jet/lang/resolve/java/descriptor/JavaConstructorDescriptor.java

@@ -74,7 +74,7 @@ public class JavaConstructorDescriptor extends ConstructorDescriptorImpl impleme
             @Nullable FunctionDescriptor original,
             @NotNull Kind kind
     ) {
-        if (kind != Kind.DECLARATION) {
+        if (kind != Kind.DECLARATION && kind != Kind.SYNTHESIZED) {
             throw new IllegalStateException("Attempt at creating a constructor that is not a declaration: \n" +
                                             "copy from: " + this + "\n" +
                                             "newOwner: " + newOwner + "\n" +

core/descriptors/src/org/jetbrains/jet/lang/descriptors/impl/ConstructorDescriptorImpl.java

@@ -112,7 +112,7 @@ public class ConstructorDescriptorImpl extends FunctionDescriptorImpl implements
             @Nullable FunctionDescriptor original,
             @NotNull Kind kind
     ) {
-        if (kind != Kind.DECLARATION) {
+        if (kind != Kind.DECLARATION && kind != Kind.SYNTHESIZED) {
             throw new IllegalStateException("Attempt at creating a constructor that is not a declaration: \n" +
                                             "copy from: " + this + "\n" +
                                             "newOwner: " + newOwner + "\n" +