Fix IDE0054 Use compound assignment

Author: vweijsters

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/DocumentationRules/FileHeaderCodeFixProvider.cs

@@ -316,7 +316,7 @@ private static SyntaxNode ReplaceHeader(Document document, SyntaxNode root, Styl
                 // Does the copyright element have leading whitespace? If so remove it.
                 if ((copyrightTriviaIndex.Value > 0) && trivia[copyrightTriviaIndex.Value - 1].IsKind(SyntaxKind.WhitespaceTrivia))
                 {
-                    copyrightTriviaIndex = copyrightTriviaIndex - 1;
+                    copyrightTriviaIndex--;
                     trivia = trivia.RemoveAt(copyrightTriviaIndex.Value);
                 }
 

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/NamingRules/RenameToUpperCaseCodeFixProvider.cs

@@ -96,7 +96,7 @@ Task<Document> RenameNamespace(CancellationToken cancellationToken)
                         && !await RenameHelper.IsValidNewMemberNameAsync(semanticModel, declaredSymbol, newName, context.CancellationToken).ConfigureAwait(false))
                     {
                         usedSuffix = true;
-                        newName = newName + Suffix;
+                        newName += Suffix;
                     }
 
                     int index = 0;

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/SpacingRules/SA1027CodeFixProvider.cs

@@ -86,7 +86,7 @@ private static TextChange FixDiagnostic(IndentationSettings indentationSettings,
                     {
                         if (useTabs)
                         {
-                            replacement.Length = replacement.Length - spaceCount;
+                            replacement.Length -= spaceCount;
                             replacement.Append('\t');
                             spaceCount = 0;
                         }
@@ -113,7 +113,7 @@ private static TextChange FixDiagnostic(IndentationSettings indentationSettings,
                                 if (offsetWithinTabColumn == 0)
                                 {
                                     // We reached a tab stop.
-                                    replacement.Length = replacement.Length - spaceCount;
+                                    replacement.Length -= spaceCount;
                                     replacement.Append('\t');
                                     spaceCount = 0;
                                 }