Create msvs_large_pdb workaround.

test/win/large-pdb/main.cc

Index: test/win/large-pdb/main.cc
diff --git a/test/win/shard/hello1.cc b/test/win/large-pdb/main.cc
similarity index 81%
copy from test/win/shard/hello1.cc
copy to test/win/large-pdb/main.cc
index 0eccf2861d5d7ed60f24d11f1a1e48c68d074c5f..adf7120dd87c9570461b85d24fdf768f309ccca1 100644
--- a/test/win/shard/hello1.cc
+++ b/test/win/large-pdb/main.cc
@@ -2,6 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-int f1() {
+int main(int argc, const char** argv) {
   return 0;
 }