[FIR] Add diagnostic CONFLICTING_PROJECTION

compiler/testData/cli/jvm/conflictingProjection.args

@@ -0,0 +1,4 @@
+$TESTDATA_DIR$/conflictingProjection.kt
+-Xuse-fir
+-d
+$TEMP_DIR$

compiler/testData/cli/jvm/conflictingProjection.kt

@@ -0,0 +1,19 @@
+class None<T>
+class In<in T>
+class Out<out T>
+
+fun a1(value: None<Int>) {}
+fun a2(value: None<in Int>) {}
+fun a3(value: None<out Int>) {}
+
+fun a7(value: Out<Int>) {}
+fun a8(value: Out<in Int>) {}
+fun a9(value: Out<out Int>) {}
+
+typealias A1<K> = None<K>
+typealias A2<K> = None<in K>
+typealias A3<K> = None<out K>
+
+typealias A13<in K> = In<K>
+typealias A14<in K> = In<in K>
+typealias A15<in K> = In<out K>

compiler/testData/cli/jvm/conflictingProjection.out

@@ -0,0 +1,16 @@
+compiler/testData/cli/jvm/conflictingProjection.kt:10:15: error: projection is conflicting with variance of the corresponding type parameter of Out<in kotlin/Int>. Remove the projection or replace it with '*'
+fun a8(value: Out<in Int>) {}
+              ^
+compiler/testData/cli/jvm/conflictingProjection.kt:17:15: error: variance annotations are only allowed for type parameters of classes and interfaces
+typealias A13<in K> = In<K>
+              ^
+compiler/testData/cli/jvm/conflictingProjection.kt:18:15: error: variance annotations are only allowed for type parameters of classes and interfaces
+typealias A14<in K> = In<in K>
+              ^
+compiler/testData/cli/jvm/conflictingProjection.kt:19:15: error: variance annotations are only allowed for type parameters of classes and interfaces
+typealias A15<in K> = In<out K>
+              ^
+compiler/testData/cli/jvm/conflictingProjection.kt:19:23: error: projection is conflicting with variance of the corresponding type parameter of In<out K>. Remove the projection or replace it with '*'
+typealias A15<in K> = In<out K>
+                      ^
+COMPILATION_ERROR