fix building error and warning in gcc10 (#3361)

* Final Cut (#3354)

* bump version

* rm pip install

Co-authored-by: tsai <caishenghang@1f-dev.kbaeegfb1x0ubnoznzequyxzve.bx.internal.cloudapp.net>

* remove windows directory (#3358)

* fix building error and warning in gcc10

Co-authored-by: Shenghang Tsai <jackalcooper@gmail.com>
Co-authored-by: tsai <caishenghang@1f-dev.kbaeegfb1x0ubnoznzequyxzve.bx.internal.cloudapp.net>
Co-authored-by: OuYang Yu <xuanjiuye@gmail.com>
Co-authored-by: Li Xinqi <lixinqi2010@gmail.com>

oneflow/core/common/cached_object_msg_allocator.h

@@ -34,7 +34,7 @@ struct ObjMsgMemBlock final {
 
   template<typename Enabled = void>
   static constexpr int MemPtrOffset() {
-    return (int)(long long)&((ObjMsgMemBlock*)nullptr)->mem_ptr_[0];
+    return offsetof(ObjMsgMemBlock, mem_ptr_);
   }
 
   ObjMsgChunk* chunk_;

oneflow/core/common/shared_or_plain.h

@@ -57,6 +57,7 @@ class SharedOrPlain final {
 template<typename S, typename P>
 SharedOrPlain<S, P>::SharedOrPlain(const SharedOrPlain& rhs) {
   if (rhs.IsPlain()) {
+#pragma GCC diagnostic ignored "-Wclass-memaccess"
     std::memcpy(this, &rhs, sizeof(*this));
   } else {
     shared_ptr_ = rhs.shared_ptr_;