Address reviewer comment

Author: Meinersbur

clang/test/Driver/clang-s-plugin.s

@@ -20,3 +20,8 @@
 
 // RUN: %clang -fplugin=%llvmshlibdir/CallSuperAttr%pluginext -fplugin-arg-testname- -fsyntax-only %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-NO-PLUGIN-ARG2
 // CHECK-NO-PLUGIN-ARG2: missing plugin argument for plugin testname in -fplugin-arg-testname-
+
+// Plugins are only relevant for the -cc1 phase. No warning should be raised
+// when only using the assembler. See GH #88173.
+// RUN: %clang -c -fpass-plugin=bar.so -fplugin=bar.so -fplugin-arg-bar-option -Werror -x assembler %s -### 2>&1 | FileCheck %s --check-prefix=CHECK-PLUGIN-ASM
+// CHECK-PLUGIN-ASM-NOT: argument unused during compilation