[FIR] KT-59368 context receiver subtyping checker

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -2105,6 +2105,12 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.SUBTYPING_BETWEEN_CONTEXT_RECEIVERS) { firDiagnostic ->
+        SubtypingBetweenContextReceiversImpl(
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.RECURSION_IN_IMPLICIT_TYPES) { firDiagnostic ->
         RecursionInImplicitTypesImpl(
             firDiagnostic as KtPsiDiagnostic,

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -1500,6 +1500,10 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = UnsupportedContextualDeclarationCall::class
     }
 
+    interface SubtypingBetweenContextReceivers : KtFirDiagnostic<KtElement> {
+        override val diagnosticClass get() = SubtypingBetweenContextReceivers::class
+    }
+
     interface RecursionInImplicitTypes : KtFirDiagnostic<PsiElement> {
         override val diagnosticClass get() = RecursionInImplicitTypes::class
     }

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -1800,6 +1800,11 @@ internal class UnsupportedContextualDeclarationCallImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtElement>(firDiagnostic, token), KtFirDiagnostic.UnsupportedContextualDeclarationCall
 
+internal class SubtypingBetweenContextReceiversImpl(
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<KtElement>(firDiagnostic, token), KtFirDiagnostic.SubtypingBetweenContextReceivers
+
 internal class RecursionInImplicitTypesImpl(
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,