Weird flags diagnostics

Usage
1

Hi! I noticed some confusing behavior in arguments parsing/diagnostics when mistyped --build:

cmake --bulid  build/RelWithDebInfo/ --parallel 8
CMake Warning:
  Ignoring extra path from command line:
 
   "8"
 
 
CMake Error: Unknown argument --parallel
2

I think CMake sees this as a configure command, which has a less strict parser for legacy compatibility