TextDiagnostic: print remark level diagnostics in bold too

The purpose of bolding these is to make them visually distinct from
continuations (supplemental note diagnostics). Therefore, the bolding applies
to all severities _including_ remarks -- it's not in any way an indicator of
priority. Also simplify and comment.

No tests.

llvm-svn: 211447
diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index 7d39c74..840c280 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -689,8 +689,9 @@
   
   printDiagnosticLevel(OS, Level, DiagOpts->ShowColors,
                        DiagOpts->CLFallbackMode);
-  printDiagnosticMessage(OS, Level, Message,
-                         OS.tell() - StartOfLocationInfo,
+  printDiagnosticMessage(OS,
+                         /*IsSupplemental*/ Level == DiagnosticsEngine::Note,
+                         Message, OS.tell() - StartOfLocationInfo,
                          DiagOpts->MessageLength, DiagOpts->ShowColors);
 }
 
@@ -735,24 +736,18 @@
     OS.resetColor();
 }
 
-/*static*/ void
-TextDiagnostic::printDiagnosticMessage(raw_ostream &OS,
-                                       DiagnosticsEngine::Level Level,
-                                       StringRef Message,
-                                       unsigned CurrentColumn, unsigned Columns,
-                                       bool ShowColors) {
+/*static*/
+void TextDiagnostic::printDiagnosticMessage(raw_ostream &OS,
+                                            bool IsSupplemental,
+                                            StringRef Message,
+                                            unsigned CurrentColumn,
+                                            unsigned Columns, bool ShowColors) {
   bool Bold = false;
-  if (ShowColors) {
-    // Print warnings, errors and fatal errors in bold, no color
-    switch (Level) {
-    case DiagnosticsEngine::Warning:
-    case DiagnosticsEngine::Error:
-    case DiagnosticsEngine::Fatal:
-      OS.changeColor(savedColor, true);
-      Bold = true;
-      break;
-    default: break; //don't bold notes
-    }
+  if (ShowColors && !IsSupplemental) {
+    // Print primary diagnostic messages in bold and without color, to visually
+    // indicate the transition from continuation notes and other output.
+    OS.changeColor(savedColor, true);
+    Bold = true;
   }
 
   if (Columns)