llvm-svn: 59491

* Move FormatError() from TextDiagnostic up to DiagClient, remove now  
  empty class TextDiagnostic
* Make DiagClient optional for Diagnostic

This fixes the following problems:

* -html-diags (and probably others) does now output the same set of  
  warnings as console clang does
* nothing crashes if one forgets to call setHeaderSearch() on  
  TextDiagnostic
* some code duplication is removed

llvm-svn: 54620

them to not be stack-allocated.

HTMLDiagnostics now batches PathDiagnostics before emitting HTML in its dtor.
This is a workaround for a problem when we trampled the Preprocessor state
when highlighting macros (sometimes resulting in an assertion failure).

llvm-svn: 50102

PathDiagnostic no longer contains a diagnostic ID or diagnostic level.

llvm-svn: 48864

Added classes "PathDiagnosticPiece", "PathDiagnostic", and "PathDiagnosticClient", which encapsulate diagnostic reporting for paths.

llvm-svn: 48861