[Wasm] Refactoring: replace "struct types" with "GC types"

In preparation for adding array types

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/BodyGenerator.kt

@@ -78,7 +78,7 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
 
     private fun generateInstanceFieldAccess(field: IrField) {
         body.buildStructGet(
-            context.referenceStructType(field.parentAsClass.symbol),
+            context.referenceGcType(field.parentAsClass.symbol),
             context.getStructFieldRef(field)
         )
     }
@@ -91,7 +91,7 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
             generateExpression(receiver)
             generateExpression(expression.value)
             body.buildStructSet(
-                struct = context.referenceStructType(field.parentAsClass.symbol),
+                struct = context.referenceGcType(field.parentAsClass.symbol),
                 fieldId = context.getStructFieldRef(field),
             )
         } else {
@@ -122,7 +122,7 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
             return
         }
 
-        val wasmStruct: WasmSymbol<WasmStructDeclaration> = context.referenceStructType(klass.symbol)
+        val wasmStruct: WasmSymbol<WasmTypeDeclaration> = context.referenceGcType(klass.symbol)
         val wasmClassId = context.referenceClassId(klass.symbol)
 
         val irFields: List<IrField> = klass.allFields(backendContext.irBuiltIns)
@@ -157,7 +157,7 @@ class BodyGenerator(val context: WasmFunctionCodegenContext) : IrElementVisitorV
         if (call.symbol == wasmSymbols.boxIntrinsic) {
             val toType = call.getTypeArgument(0)!!
             val klass = toType.erasedUpperBound!!
-            val structTypeName = context.referenceStructType(klass.symbol)
+            val structTypeName = context.referenceGcType(klass.symbol)
             val klassId = context.referenceClassId(klass.symbol)
 
             body.buildConstI32Symbol(klassId)

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/DeclarationGenerator.kt

@@ -183,7 +183,7 @@ class DeclarationGenerator(val context: WasmModuleCodegenContext) : IrElementVis
                 }
             )
 
-            context.defineStructType(symbol, structType)
+            context.defineGcType(symbol, structType)
 
             var depth = 2
             val metadata = context.getClassMetadata(symbol)

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/TypeTransformer.kt

@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.types.classifierOrNull
 import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.util.getInlineClassUnderlyingType
@@ -47,7 +46,7 @@ class WasmTypeTransformer(
         }
 
     fun IrType.toStructType(): WasmType =
-        WasmRefNullType(WasmHeapType.Type(context.referenceStructType(erasedUpperBound?.symbol ?: builtIns.anyClass)))
+        WasmRefNullType(WasmHeapType.Type(context.referenceGcType(erasedUpperBound?.symbol ?: builtIns.anyClass)))
 
     fun IrType.toBoxedInlineClassType(): WasmType =
         toStructType()

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmBaseCodegenContext.kt

@@ -21,7 +21,7 @@ interface WasmBaseCodegenContext {
 
     fun referenceFunction(irFunction: IrFunctionSymbol): WasmSymbol<WasmFunction>
     fun referenceGlobal(irField: IrFieldSymbol): WasmSymbol<WasmGlobal>
-    fun referenceStructType(irClass: IrClassSymbol): WasmSymbol<WasmStructDeclaration>
+    fun referenceGcType(irClass: IrClassSymbol): WasmSymbol<WasmTypeDeclaration>
     fun referenceFunctionType(irFunction: IrFunctionSymbol): WasmSymbol<WasmFunctionType>
 
     fun referenceClassId(irClass: IrClassSymbol): WasmSymbol<Int>

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmCompiledModuleFragment.kt

@@ -20,8 +20,8 @@ class WasmCompiledModuleFragment {
         ReferencableAndDefinable<IrFieldSymbol, WasmGlobal>()
     val functionTypes =
         ReferencableAndDefinable<IrFunctionSymbol, WasmFunctionType>()
-    val structTypes =
-        ReferencableAndDefinable<IrClassSymbol, WasmStructDeclaration>()
+    val gcTypes =
+        ReferencableAndDefinable<IrClassSymbol, WasmTypeDeclaration>()
     val classIds =
         ReferencableElements<IrClassSymbol, Int>()
     val interfaceId =
@@ -88,7 +88,7 @@ class WasmCompiledModuleFragment {
         bind(functions.unbound, functions.defined)
         bind(globals.unbound, globals.defined)
         bind(functionTypes.unbound, functionTypes.defined)
-        bind(structTypes.unbound, structTypes.defined)
+        bind(gcTypes.unbound, gcTypes.defined)
         bind(runtimeTypes.unbound, runtimeTypes.defined)
 
         val klassIds = mutableMapOf<IrClassSymbol, Int>()
@@ -162,7 +162,7 @@ class WasmCompiledModuleFragment {
 
         val module = WasmModule(
             functionTypes = functionTypes.elements,
-            structs = structTypes.elements,
+            gcTypes = gcTypes.elements,
             importsInOrder = importedFunctions,
             importedFunctions = importedFunctions,
             definedFunctions = functions.elements.filterIsInstance<WasmFunction.Defined>(),

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmModuleCodegenContext.kt

@@ -19,7 +19,7 @@ import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 interface WasmModuleCodegenContext : WasmBaseCodegenContext {
     fun defineFunction(irFunction: IrFunctionSymbol, wasmFunction: WasmFunction)
     fun defineGlobal(irField: IrFieldSymbol, wasmGlobal: WasmGlobal)
-    fun defineStructType(irClass: IrClassSymbol, wasmStruct: WasmStructDeclaration)
+    fun defineGcType(irClass: IrClassSymbol, wasmType: WasmTypeDeclaration)
     fun defineRTT(irClass: IrClassSymbol, wasmGlobal: WasmGlobal)
     fun defineFunctionType(irFunction: IrFunctionSymbol, wasmFunctionType: WasmFunctionType)
     fun addJsFun(importName: String, jsCode: String)

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/ir2wasm/WasmModuleCodegenContextImpl.kt

@@ -92,8 +92,8 @@ class WasmModuleCodegenContextImpl(
         wasmFragment.globals.define(irField, wasmGlobal)
     }
 
-    override fun defineStructType(irClass: IrClassSymbol, wasmStruct: WasmStructDeclaration) {
-        wasmFragment.structTypes.define(irClass, wasmStruct)
+    override fun defineGcType(irClass: IrClassSymbol, wasmStruct: WasmTypeDeclaration) {
+        wasmFragment.gcTypes.define(irClass, wasmStruct)
     }
 
     override fun defineRTT(irClass: IrClassSymbol, wasmGlobal: WasmGlobal) {
@@ -122,12 +122,12 @@ class WasmModuleCodegenContextImpl(
     override fun referenceGlobal(irField: IrFieldSymbol): WasmSymbol<WasmGlobal> =
         wasmFragment.globals.reference(irField)
 
-    override fun referenceStructType(irClass: IrClassSymbol): WasmSymbol<WasmStructDeclaration> {
+    override fun referenceGcType(irClass: IrClassSymbol): WasmSymbol<WasmTypeDeclaration> {
         val type = irClass.defaultType
         require(!type.isNothing()) {
             "Can't reference Nothing type"
         }
-        return wasmFragment.structTypes.reference(irClass)
+        return wasmFragment.gcTypes.reference(irClass)
     }
 
     override fun referenceClassRTT(irClass: IrClassSymbol): WasmSymbol<WasmGlobal> =