[FIR] Add diagnostic CONFLICTING_OVERLOADS & REDECLARATION

compiler/fir/analysis-tests/testData/resolveWithStdlib/callableReferences/beyoundCalls.kt

@@ -1,5 +1,5 @@
-fun bar(x: String): Int = 1
-fun bar(x: String): Double = 1
+<!CONFLICTING_OVERLOADS!>fun bar(x: String): Int = 1<!>
+<!CONFLICTING_OVERLOADS!>fun bar(x: String): Double = 1<!>
 
 fun baz(x: String): Int = 1
 fun <T, R> foobaz(x: T): R = TODO()

compiler/fir/analysis-tests/testData/resolveWithStdlib/lowPriorityInResolution.kt

@@ -1,8 +1,8 @@
-@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+<!CONFLICTING_OVERLOADS!>@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
 <!HIDDEN!>@kotlin.internal.LowPriorityInOverloadResolution<!>
-fun foo(): Int = 1
+fun foo(): Int = 1<!>
 
-fun foo(): String = ""
+<!CONFLICTING_OVERLOADS!>fun foo(): String = ""<!>
 
 fun test() {
     val s = foo()

compiler/fir/analysis-tests/testData/resolveWithStdlib/problems.kt

@@ -13,7 +13,7 @@ fun test() {
 val Any.bar get() = "456"
 val String.bar get() = "987"
 
-val t = "".bar
+<!REDECLARATION!>val t = "".bar<!>
 
 val p = Pair(0, "")
 
@@ -21,4 +21,4 @@ class Base<T>(val x: T)
 class Derived : Base<Int>(10)
 val xx = Derived().x + 1
 
-val t = throw AssertionError("")
+<!REDECLARATION!>val t = throw AssertionError("")<!>