[cfe-dev] #error and #warning: why include "#error/#warning" in the diagnostic?

[Ted Kremenek]

I received some feedback from some users who wondered why #error/#warning diagnostics include the actual "#error" in the diagnostic, e.g.:

  t.c:1:2: error: #error this is an error

This seems redundant.  Is this necessary?  Why not just have:

  t.c:1:2: error: this is an error

Is there a reason the '#error' needs to be there?