[NFC] [Serialization] Emit Name for DECL_EXPORT

Author: ChuanqiXu9

clang/lib/Serialization/ASTWriter.cpp

@@ -1049,6 +1049,7 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(DECL_UNRESOLVED_USING_VALUE);
   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
   RECORD(DECL_LINKAGE_SPEC);
+  RECORD(DECL_EXPORT);
   RECORD(DECL_CXX_RECORD);
   RECORD(DECL_CXX_METHOD);
   RECORD(DECL_CXX_CONSTRUCTOR);

clang/test/Modules/no-implicit-declarations.cppm

@@ -17,7 +17,7 @@ export int a = 43;
 // CHECK:  <DECLTYPES_BLOCK
 // CHECK-NOT: <DECL_TYPEDEF
 // CHECK:    <DECL_CONTEXT_LEXICAL
-// CHECK:    <UnknownCode
+// CHECK:    <DECL_EXPORT
 // CHECK:    <TYPE_TYPEDEF
 // CHECK:    <DECL_VAR
 // CHECK:    <EXPR_INTEGER_LITERAL