Add a symlink to the verilator UART pseudo device for testing

Allow unique device file name to be used in bazel test

Change-Id: I04adc6ac4cd7d520207d4adc3fce2f1149ed1cbc

hw/dv/dpi/uartdpi/uartdpi.c

diff --git a/hw/dv/dpi/uartdpi/uartdpi.c b/hw/dv/dpi/uartdpi/uartdpi.c
index 479162f..e08f1e2 100644
--- a/hw/dv/dpi/uartdpi/uartdpi.c
+++ b/hw/dv/dpi/uartdpi/uartdpi.c
@@ -47,6 +47,16 @@
       "$ screen %s\n",
       ctx->ptyname, name, ctx->ptyname);
 
+  const char *test_out_dir = getenv("TEST_UNDECLARED_OUTPUTS_DIR");
+  const int kMaxPathLen = 512;
+  if (test_out_dir) {
+    char device_file[kMaxPathLen] = {0};
+    snprintf(device_file, kMaxPathLen, "%s/%s_device", test_out_dir, name);
+    if (symlink(ctx->ptyname, device_file) == 0) {
+      printf("Created symlink device %s for %s.\n", device_file, name);
+    }
+  }
+
   // Open log file (if requested)
   ctx->log_file = NULL;
   bool write_log_file = strlen(log_file_path) != 0;
@@ -57,8 +67,6 @@
 
     } else {
       FILE *log_file;
-      const char *test_out_dir = getenv("TEST_UNDECLARED_OUTPUTS_DIR");
-      const int kMaxPathLen = 512;
       char test_out_log_file[kMaxPathLen] = {0};
       if (test_out_dir) {
         snprintf(test_out_log_file, kMaxPathLen, "%s/%s", test_out_dir,