Use isStringEnumShape, reorder when conditions

Author: lauzadis

codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/XmlParserGenerator.kt

@@ -579,7 +579,15 @@ open class XmlParserGenerator(
         val parseFn = when {
             target.type == ShapeType.BLOB -> writer.format("#T { it.#T() } ", RuntimeTypes.Serde.parse, RuntimeTypes.Core.Text.Encoding.decodeBase64Bytes)
             target.type == ShapeType.BOOLEAN -> writer.format("#T()", RuntimeTypes.Serde.parseBoolean)
-            target.type == ShapeType.STRING && !target.hasTrait<EnumTrait>() -> {
+            target.isStringEnumShape -> {
+                if (!textExprIsResult) {
+                    writer.write("#T.fromValue(#L)", ctx.symbolProvider.toSymbol(target), textExpr)
+                    return
+                } else {
+                    writer.format("#T { #T.fromValue(it) } ", RuntimeTypes.Serde.parse, ctx.symbolProvider.toSymbol(target))
+                }
+            }
+            target.type == ShapeType.STRING -> {
                 if (!textExprIsResult) {
                     writer.write(textExpr)
                     return
@@ -601,14 +609,6 @@ open class XmlParserGenerator(
             target.type == ShapeType.DOUBLE -> writer.format("#T()", RuntimeTypes.Serde.parseDouble)
             target.type == ShapeType.BIG_DECIMAL -> writer.format("#T()", RuntimeTypes.Serde.parseBigDecimal)
             target.type == ShapeType.BIG_INTEGER -> writer.format("#T()", RuntimeTypes.Serde.parseBigInteger)
-            target.type == ShapeType.ENUM || (target.type == ShapeType.STRING && target.hasTrait<EnumTrait>()) -> {
-                if (!textExprIsResult) {
-                    writer.write("#T.fromValue(#L)", ctx.symbolProvider.toSymbol(target), textExpr)
-                    return
-                } else {
-                    writer.format("#T { #T.fromValue(it) } ", RuntimeTypes.Serde.parse, ctx.symbolProvider.toSymbol(target))
-                }
-            }
             target.type == ShapeType.INT_ENUM -> {
                 writer.format("#T { #T.fromValue(it.toInt()) } ", RuntimeTypes.Serde.parse, ctx.symbolProvider.toSymbol(target))
             }