IR: add IrSimpleFunction.isInfix

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -396,7 +396,8 @@ class Fir2IrDeclarationStorage(
                     isSuspend = isSuspend,
                     isExpect = simpleFunction?.isExpect == true,
                     isFakeOverride = updatedOrigin == IrDeclarationOrigin.FAKE_OVERRIDE,
-                    isOperator = simpleFunction?.isOperator == true
+                    isOperator = simpleFunction?.isOperator == true,
+                    isInfix = simpleFunction?.isInfix == true
                 ).apply {
                     metadata = FirMetadataSource.Function(function)
                     convertAnnotationsFromLibrary(function)
@@ -520,7 +521,7 @@ class Fir2IrDeclarationStorage(
                 isExternal = propertyAccessor?.isExternal == true,
                 isTailrec = false, isSuspend = false, isExpect = false,
                 isFakeOverride = origin == IrDeclarationOrigin.FAKE_OVERRIDE,
-                isOperator = false
+                isOperator = false, isInfix = false
             ).apply {
                 correspondingPropertySymbol = correspondingProperty.symbol
                 if (propertyAccessor != null) {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt

@@ -260,7 +260,8 @@ class DataClassMembersGenerator(val components: Fir2IrComponents) {
                     isSuspend = false,
                     isExpect = false,
                     isFakeOverride = false,
-                    isOperator = false
+                    isOperator = false,
+                    isInfix = false
                 ).apply {
                     if (otherParameterNeeded) {
                         val irValueParameter = createSyntheticIrParameter(

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DelegatedMemberGenerator.kt

@@ -129,6 +129,7 @@ internal class DelegatedMemberGenerator(
                 superFunction.isTailrec,
                 superFunction.isSuspend,
                 superFunction.isOperator,
+                superFunction.isInfix,
                 superFunction.isExpect
             ).apply {
                 descriptor.bind(this)

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazySimpleFunction.kt

@@ -51,6 +51,9 @@ class Fir2IrLazySimpleFunction(
     override val isOperator: Boolean
         get() = fir.isOperator
 
+    override val isInfix: Boolean
+        get() = fir.isInfix
+
     @ObsoleteDescriptorBasedAPI
     override val descriptor: FunctionDescriptor
         get() = super.descriptor as FunctionDescriptor