Introduce StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME

and use it instead of hardcoded constant

analysis/analysis-api-fe10/src/org/jetbrains/kotlin/analysis/api/descriptors/symbols/descriptorBased/KtFe10DescValueParameterSymbol.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.analysis.api.symbols.KtValueParameterSymbol
 import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtPsiBasedSymbolPointer
 import org.jetbrains.kotlin.analysis.api.symbols.pointers.KtSymbolPointer
 import org.jetbrains.kotlin.analysis.api.types.KtType
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.descriptors.impl.AnonymousFunctionDescriptor
 import org.jetbrains.kotlin.name.Name
@@ -54,7 +55,7 @@ internal class KtFe10DescValueParameterSymbol(
     override val isImplicitLambdaParameter: Boolean
         get() = withValidityAssertion {
             descriptor.containingDeclaration is AnonymousFunctionDescriptor &&
-                    descriptor.name.identifierOrNullIfSpecial == "it" &&
+                    descriptor.name == StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME &&
                     // Implicit lambda parameter doesn't have a source PSI.
                     descriptor.source.getPsi() == null &&
                     // But, that could be the case for a declaration from Library. Double-check the slice in the binding context

analysis/analysis-api-fe10/src/org/jetbrains/kotlin/analysis/api/descriptors/symbols/descriptorBased/base/Kt1DescUtils.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.analysis.api.types.KtType
 import org.jetbrains.kotlin.analysis.api.types.KtTypeNullability
 import org.jetbrains.kotlin.analysis.utils.errors.unexpectedElementError
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.builtins.functions.FunctionClassDescriptor
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
@@ -349,7 +350,7 @@ internal fun DeclarationDescriptor.getSymbolOrigin(analysisContext: Fe10Analysis
         return analysisContext.getOrigin(virtualFile)
     } else { // psi == null
         // Implicit lambda parameter
-        if (this is ValueParameterDescriptor && this.name.identifierOrNullIfSpecial == "it") {
+        if (this is ValueParameterDescriptor && this.name == StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME) {
             return KtSymbolOrigin.SOURCE_MEMBER_GENERATED
         }
     }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirCallCompleter.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.resolve.inference
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.fakeElement
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.declarations.FirAnonymousFunction
@@ -258,7 +259,7 @@ class FirCallCompleter(
 
             val itParam = when {
                 needItParam -> {
-                    val name = Name.identifier("it")
+                    val name = StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME
                     val itType = parameters.single()
                     buildValueParameter {
                         resolvePhase = FirResolvePhase.BODY_RESOLVE

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirDeclarationsResolveTransformer.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.resolve.transformers.body.resolve
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.fakeElement
@@ -905,7 +906,7 @@ open class FirDeclarationsResolveTransformer(
         val singleParameterType = resolvedLambdaAtom.parameters.singleOrNull()
         return when {
             lambda.valueParameters.isEmpty() && singleParameterType != null -> {
-                val name = Name.identifier("it")
+                val name = StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME
                 val itParam = buildValueParameter {
                     resolvePhase = FirResolvePhase.BODY_RESOLVE
                     source = lambda.source?.fakeElement(KtFakeSourceElementKind.ItLambdaParameter)

compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt

@@ -333,7 +333,7 @@ class FunctionDescriptorResolver(
                 // it parameter for lambda
                 val valueParameterDescriptor = expectedValueParameters.single()
                 val it = ValueParameterDescriptorImpl(
-                    functionDescriptor, null, 0, Annotations.EMPTY, Name.identifier("it"),
+                    functionDescriptor, null, 0, Annotations.EMPTY, StandardNames.IMPLICIT_LAMBDA_PARAMETER_NAME,
                     expectedParameterTypes!!.single(), valueParameterDescriptor.declaresDefaultValue(),
                     valueParameterDescriptor.isCrossinline, valueParameterDescriptor.isNoinline,
                     valueParameterDescriptor.varargElementType, SourceElement.NO_SOURCE

core/compiler.common/src/org/jetbrains/kotlin/builtins/StandardNames.kt

@@ -38,6 +38,8 @@ object StandardNames {
 
     @JvmField val NEXT_CHAR = Name.identifier("nextChar")
 
+    @JvmField val IMPLICIT_LAMBDA_PARAMETER_NAME = Name.identifier("it")
+
     @JvmField val CONTEXT_FUNCTION_TYPE_PARAMETER_COUNT_NAME = Name.identifier("count")
 
     @JvmField val DYNAMIC_FQ_NAME = FqName("<dynamic>")