Fix a bug that was breaking the build in 32-bit mode.  For 32-bit, sizeof(int) = sizeof(long) and the build failed on "call of overloaded 'toStr(long int)' is ambiguous."
Fix a bug that was breaking the build in 32-bit mode.  For 32-bit,
sizeof(int) = sizeof(long) and the build failed on "call of overloaded
'toStr(long int)' is ambiguous."

I'm not sure why StrUtil::toStr(long) is ambiguous, but it's easy
enough to fix.  Bad C++, bad, bad, awful, naughty C++.

HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit