Make strtod_c compatible with different gcc abi (#21293)
Summary:
We have encountered `std::bad_cast` error when running PyTorch binary built with cxx11 abi on CentOS7, stack trace:
```
#0 0x00007fec10160207 in raise () from /lib64/libc.so.6
#1 0x00007fec101618f8 in abort () from /lib64/libc.so.6
#2 0x00007fec015767d5 in __gnu_cxx::__verbose_terminate_handler() () from /lib64/libstdc++.so.6
#3 0x00007fec01574746 in ?? () from /lib64/libstdc++.so.6
#4 0x00007fec01574773 in std::terminate() () from /lib64/libstdc++.so.6
#5 0x00007fec01574993 in __cxa_throw () from /lib64/libstdc++.so.6
#6 0x00007fec015c94d2 in std::__throw_bad_cast() () from /lib64/libstdc++.so.6
#7 0x00007feb2ab3c2d7 in std::__cxx11::numpunct<char> const& std::use_facet<std::__cxx11::numpunct<char> >(std::locale const&) ()
from /root/.local/lib/python2.7/site-packages/torch/lib/libcaffe2.so
#8 0x00007feb28643d62 in torch::jit::script::strtod_c(char const*, char**) () from /root/.local/lib/python2.7/site-packages/torch/lib/libcaffe2.so
```
We are suspecting this line will get compiled to gcc abi dependent symbol:
```
char decimal_point = std::use_facet<std::numpunct<char>>(std::locale()).decimal_point();
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21293
Differential Revision: D15609910
Pulled By: bddppq
fbshipit-source-id: e247059729863868e4b36d6fec4fcbc36fbc4bb1
