Reduce allocations in calls to WithAnnotationsGreen

Each caller changed was allocating more than necessary:

1) List object created
2) If GetAnnotations isn't empty, there was an array allocated in the list
3) The Add calls would always allocate (even when constructed with a non-empty GetAnnotations result)
4) ToArray allocation

Instead, there is just a single array allocation.

I don't expect this to have a huge effect, but there are 35 MB of List/array of SyntaxAnnotations allocated in the speedometer trace I'm looking at during the typing scenario (about 0.5% of allocations)

Author: ToddGrun

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/InternalSyntax/MarkupEndTagSyntax.cs

@@ -22,14 +22,5 @@ public bool IsMarkupTransition
     }
 
     public MarkupEndTagSyntax AsMarkupTransition()
-    {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(MarkupTransitionKey, new object())
-            };
-
-        var newGreen = this.WithAnnotationsGreen(annotations.ToArray());
-
-        return newGreen;
-    }
+        =>  this.WithAnnotationsGreen([.. GetAnnotations(), new(MarkupTransitionKey, new object())]);
 }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/InternalSyntax/MarkupStartTagSyntax.cs

@@ -22,14 +22,5 @@ public bool IsMarkupTransition
     }
 
     public MarkupStartTagSyntax AsMarkupTransition()
-    {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(MarkupTransitionKey, new object())
-            };
-
-        var newGreen = this.WithAnnotationsGreen(annotations.ToArray());
-
-        return newGreen;
-    }
+        => this.WithAnnotationsGreen([.. GetAnnotations(), new(MarkupTransitionKey, new object())]);
 }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/InternalSyntax/RazorDirectiveSyntax.cs

@@ -22,14 +22,5 @@ public DirectiveDescriptor DirectiveDescriptor
     }
 
     public RazorDirectiveSyntax WithDirectiveDescriptor(DirectiveDescriptor descriptor)
-    {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(DirectiveDescriptorKey, descriptor)
-            };
-
-        var newGreen = this.WithAnnotationsGreen(annotations.ToArray());
-
-        return newGreen;
-    }
+        => this.WithAnnotationsGreen([.. GetAnnotations(), new(DirectiveDescriptorKey, descriptor)]);
 }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/MarkupMinimizedTagHelperAttributeSyntax.cs

@@ -22,12 +22,7 @@ public TagHelperAttributeInfo TagHelperAttributeInfo
 
     public MarkupMinimizedTagHelperAttributeSyntax WithTagHelperAttributeInfo(TagHelperAttributeInfo info)
     {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(TagHelperAttributeInfoKey, info)
-            };
-
-        var newGreen = Green.WithAnnotationsGreen(annotations.ToArray());
+        var newGreen = Green.WithAnnotationsGreen([.. GetAnnotations(), new(TagHelperAttributeInfoKey, info)]);
 
         return (MarkupMinimizedTagHelperAttributeSyntax)newGreen.CreateRed(Parent, Position);
     }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/MarkupMinimizedTagHelperDirectiveAttributeSyntax.cs

@@ -35,12 +35,7 @@ public string FullName
 
     public MarkupMinimizedTagHelperDirectiveAttributeSyntax WithTagHelperAttributeInfo(TagHelperAttributeInfo info)
     {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(TagHelperAttributeInfoKey, info)
-            };
-
-        var newGreen = Green.WithAnnotationsGreen(annotations.ToArray());
+        var newGreen = Green.WithAnnotationsGreen([.. GetAnnotations(), new(TagHelperAttributeInfoKey, info)]);
 
         return (MarkupMinimizedTagHelperDirectiveAttributeSyntax)newGreen.CreateRed(Parent, Position);
     }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/MarkupTagHelperAttributeSyntax.cs

@@ -22,12 +22,7 @@ public TagHelperAttributeInfo TagHelperAttributeInfo
 
     public MarkupTagHelperAttributeSyntax WithTagHelperAttributeInfo(TagHelperAttributeInfo info)
     {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(TagHelperAttributeInfoKey, info)
-            };
-
-        var newGreen = Green.WithAnnotationsGreen(annotations.ToArray());
+        var newGreen = Green.WithAnnotationsGreen([.. GetAnnotations(), new(TagHelperAttributeInfoKey, info)]);
 
         return (MarkupTagHelperAttributeSyntax)newGreen.CreateRed(Parent, Position);
     }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/MarkupTagHelperDirectiveAttributeSyntax.cs

@@ -35,12 +35,7 @@ public string FullName
 
     public MarkupTagHelperDirectiveAttributeSyntax WithTagHelperAttributeInfo(TagHelperAttributeInfo info)
     {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(TagHelperAttributeInfoKey, info)
-            };
-
-        var newGreen = Green.WithAnnotationsGreen(annotations.ToArray());
+        var newGreen = Green.WithAnnotationsGreen([.. GetAnnotations(), new(TagHelperAttributeInfoKey, info)]);
 
         return (MarkupTagHelperDirectiveAttributeSyntax)newGreen.CreateRed(Parent, Position);
     }

src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Syntax/RazorDirectiveSyntax.cs

@@ -22,12 +22,7 @@ public DirectiveDescriptor DirectiveDescriptor
 
     public RazorDirectiveSyntax WithDirectiveDescriptor(DirectiveDescriptor descriptor)
     {
-        var annotations = new List<SyntaxAnnotation>(GetAnnotations())
-            {
-                new SyntaxAnnotation(DirectiveDescriptorKey, descriptor)
-            };
-
-        var newGreen = Green.WithAnnotationsGreen(annotations.ToArray());
+        var newGreen = Green.WithAnnotationsGreen([.. GetAnnotations(), new(DirectiveDescriptorKey, descriptor)]);
 
         return (RazorDirectiveSyntax)newGreen.CreateRed(Parent, Position);
     }