[FIR] Add diagnostic CONFLICTING_OVERLOADS & REDECLARATION

compiler/testData/diagnostics/tests/multiplatform/headerClass/expectDeclarationWithWeakIncompatibilities.fir.kt

@@ -23,6 +23,6 @@ actual var s: String = "value"
 
 fun foo2(): Int = 0
 
-actual class Foo3
+<!REDECLARATION!>actual class Foo3<!>
 
-class Foo3
+<!REDECLARATION!>class Foo3<!>

compiler/testData/diagnostics/tests/multiplatform/topLevelFun/conflictingHeaderDeclarations.fir.kt

@@ -1,8 +0,0 @@
-// !LANGUAGE: +MultiPlatformProjects
-// MODULE: m1-common
-// FILE: common.kt
-
-expect fun foo()
-expect fun foo()
-
-expect fun foo(x: Int)

compiler/testData/diagnostics/tests/multiplatform/topLevelFun/conflictingHeaderDeclarations.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: +MultiPlatformProjects
 // MODULE: m1-common
 // FILE: common.kt

compiler/testData/diagnostics/tests/multiplatform/topLevelFun/conflictingImplDeclarations.fir.kt

@@ -7,11 +7,11 @@ expect fun foo()
 // MODULE: m2-jvm(m1-common)
 // FILE: jvm.kt
 
-actual fun foo() {}
-actual fun foo() {}
+<!CONFLICTING_OVERLOADS!>actual fun foo() {}<!>
+<!CONFLICTING_OVERLOADS!>actual fun foo() {}<!>
 
 // MODULE: m3-js(m1-common)
 // FILE: js.kt
 
-actual fun foo() {}
-actual fun foo() {}
+<!CONFLICTING_OVERLOADS!>actual fun foo() {}<!>
+<!CONFLICTING_OVERLOADS!>actual fun foo() {}<!>

compiler/testData/diagnostics/tests/multiplatform/topLevelFun/headerDeclarationWithBody.fir.kt

@@ -2,8 +2,8 @@
 // MODULE: m1-common
 // FILE: common.kt
 
-expect fun foo()
+<!CONFLICTING_OVERLOADS!>expect fun foo()<!>
 
-expect fun foo() {}
+<!CONFLICTING_OVERLOADS!>expect fun foo() {}<!>
 
 expect fun bar() {}