Unresolved name error in 'inherit' member reported multiple times

[auduchinok]

Consider this code with a single undefined name error:

type T() =
    inherit Foo()

Both FCS and fsc produce three errors for this one error in code:

Program.fs(4,13): Error FS0039 : The type 'Foo' is not defined.
Program.fs(4,13): Error FS0039 : The type 'Foo' is not defined.
Program.fs(4,13): Error FS0039 : The type 'Foo' is not defined.

This is bad for two reasons:

• the user sees error duplicates
• it shows that there's likely a duplicated analysis somewhere, which affects perfomance

[edgarfgp]

This is quite annoying and verbose to have 3X most of the diagnostics. Imagine having 10 errors that became 30 :(