[clangd] Fix MSVC build failure.

http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-windows10pro-fast/builds/26898

llvm-svn: 365844
diff --git a/clang-tools-extra/clangd/AST.cpp b/clang-tools-extra/clangd/AST.cpp
index 2f401f2..642b30c 100644
--- a/clang-tools-extra/clangd/AST.cpp
+++ b/clang-tools-extra/clangd/AST.cpp
@@ -184,7 +184,7 @@
     DifferentAt++;
   }
 
-  for (u_int i = DifferentAt; i < OriginalParts.size(); ++i) {
+  for (unsigned i = DifferentAt; i < OriginalParts.size(); ++i) {
     Result.push_back(OriginalParts[i]);
   }
   return join(Result, "::");