tests: net: lib: http_server: Disable erroneous warning from clang

The warning emitted is:

tests/net/lib/http_server/core/src/main.c:1400:19: error: variable
'http1_header_capture_common_response' is not needed and will not be
emitted [-Werror,-Wunneeded-internal-declaration]
static const char http1_header_capture_common_response[]
                  ^                             = "HTTP/1.1 200\r\n"

However, this variable is needed at compile-time since it's referenced
via sizeof(). This appears to be the same as this clang bug:
llvm/llvm-project#25458.

This warning only started being emitted when I re-enabled the
-Wunused-function warning for clang.

Signed-off-by: Tom Hughes <[email protected]>

Author: thughes

tests/net/lib/http_server/core/src/main.c

@@ -1416,11 +1416,14 @@ ZTEST(server_function_tests, test_http2_rst_stream)
 	zassert_equal(ret, 0, "Connection should've been closed");
 }
 
+/* Disable erroneous warning: https://github.com/llvm/llvm-project/issues/25458. */
+TOOLCHAIN_DISABLE_CLANG_WARNING("-Wunneeded-internal-declaration")
 static const char http1_header_capture_common_response[] = "HTTP/1.1 200\r\n"
 							   "Transfer-Encoding: chunked\r\n"
 							   "Content-Type: text/plain\r\n"
 							   "\r\n"
 							   "0\r\n\r\n";
+TOOLCHAIN_ENABLE_CLANG_WARNING("-Wunneeded-internal-declaration")
 
 static void test_http1_header_capture_common(const char *request)
 {