[vcpkg] fix vs2015 build (#14659)

toolsrc/include/vcpkg/base/lockguarded.h

@@ -29,7 +29,7 @@ namespace vcpkg::Util
         LockGuardPtr(LockGuarded<T>& sync) : m_lock(sync.m_mutex), m_ptr(sync.m_t) { }
 
     private:
-        std::lock_guard<std::mutex> m_lock;
+        std::unique_lock<std::mutex> m_lock;
         T& m_ptr;
     };
 }

toolsrc/src/vcpkg/build.cpp

@@ -214,7 +214,7 @@ namespace vcpkg::Build
 
     static std::remove_const_t<decltype(ALL_POLICIES)> generate_all_policies()
     {
-        std::remove_const_t<decltype(ALL_POLICIES)> res;
+        std::remove_const_t<decltype(ALL_POLICIES)> res{};
         for (size_t i = 0; i < res.size(); ++i)
         {
             res[i] = static_cast<BuildPolicy>(i);