Remove include of <utility> from seh.cpp (dotnet/coreclr#6359)

Remove include of <utility> from seh.cpp (dotnet/coreclr#6359)

In my previous change that made exceptions smaller, I had `#include <utility>`
and I haven't realized that it pulls in some stl headers. That breaks build
on ARM.
The fix is to replace that include by defining just the std::move that's
all that was needed from the header.

Commit migrated from https://github.com/dotnet/coreclr/commit/32a020e47a0797bba4167e85efc38a34397f633e