EnvironmentTest crashes when /proc is unavailable #45901

Core was generated by `out/Release/cctest --gtest_filter=*'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0xf7524644 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_assign(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) () from /usr/lib/libstdc++.so.6
[Current thread is 1 (LWP 4574)]
(gdb) bt
#0  0xf7524644 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_assign(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) () from /usr/lib/libstdc++.so.6
#1  0x56da0c64 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::assign (__str=..., 
    this=0xf2d7d424) at /usr/include/c++/8.5.0/bits/basic_string.h:1370
#2  std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::operator= (__str=..., this=0xf2d7d424)
    at /usr/include/c++/8.5.0/bits/basic_string.h:699
#3  node::GetExecPath (argv=...) at ../../src/env.cc:313
#4  0x56dab741 in node::Environment::Environment (this=<optimized out>, isolate_data=<optimized out>, isolate=<optimized out>, 
    args=..., exec_args=..., env_info=<optimized out>, flags=<optimized out>, thread_id=...) at ../../src/env.cc:359
#5  0x56dad8ac in node::Environment::Environment (this=0xf2d7d020, isolate_data=0xf569e9c0, context=..., args=..., 
    exec_args=..., env_info=0x0, flags=node::EnvironmentFlags::kDefaultFlags, thread_id=...) at ../../src/env.cc:436
#6  0x56d5e2da in node::CreateEnvironment (isolate_data=isolate_data@entry=0xf569e9c0, context=context@entry=..., args=..., 
    exec_args=..., flags=node::EnvironmentFlags::kDefaultFlags, thread_id=..., inspector_parent_handle=...)
    at ../../src/api/environment.cc:345
#7  0x56d101b9 in EnvironmentTest_NestedMicrotaskQueue_Test::TestBody (this=0xf2e8a370)
    at ../../test/cctest/test_environment.cc:677