Fix clang_check and lite failures (#5680)
Summary:
This PR fixes two test failures:
1. clang check:
```
third-party/folly/folly/detail/Futex.cpp:52:12: error: implicit conversion loses integer precision: 'long' to 'int' [-Werror,-Wshorten-64-to-32]
int rv = syscall(
~~ ^~~~~~~~
third-party/folly/folly/detail/Futex.cpp:114:12: error: implicit conversion loses integer precision: 'long' to 'int' [-Werror,-Wshorten-64-to-32]
int rv = syscall(
~~ ^~~~~~~~
```
2. lite
```
./third-party/folly/folly/synchronization/DistributedMutex-inl.h:1337:7: error: exception handling disabled, use -fexceptions to enable
} catch (...) {
^
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5680
Differential Revision: D16704042
Pulled By: miasantreble
fbshipit-source-id: a53cb06128365d9e864f07476b0af8fc27140f07
Zhongyi Xie
e0b84538af