Currently, lldb fails to build with the following errors when MSVS update 3 is used:
> fatal error C1001: An internal error has occurred in the compiler.
> (compiler file 'msc1.cpp', line 1468)
> To work around this problem, try simplifying or changing the program near the locations listed above.
Seems it is relative with the `constexpr`. This patch simplifies the code a bit and allows it to compile and run.