Background

PR #12957 introduced the deferred tag helper lowering pipeline, which added several IR node types with ElementOrTagHelper in their names. During code review, it was noted these would be clearer as UnresolvedElement since they represent elements that haven't yet been resolved as tag helpers.

What to change

Rename the following types and update all references:

• MarkupOrTagHelperElementIntermediateNode → UnresolvedElementIntermediateNode (or similar)
• MarkupOrTagHelperAttributeIntermediateNode → UnresolvedAttributeIntermediateNode
• MarkupOrTagHelperAttributeValueIntermediateNode → UnresolvedAttributeValueIntermediateNode
• CSharpOrTagHelperExpressionAttributeValueIntermediateNode → UnresolvedExpressionAttributeValueIntermediateNode

Files to update

• Node definitions: src/Compiler/Microsoft.CodeAnalysis.Razor.Compiler/src/Language/Intermediate/
• Lowering phase: DefaultRazorIntermediateNodeLoweringPhase.cs
• Resolution phase: DefaultTagHelperResolutionPhase*.cs
• IR baselines in test files (.ir.txt files)
• Any references in IntermediateNodeVisitor, IntermediateNodeWalker, etc.

Notes

• This is a pure rename refactoring — no behavioral changes.
• IR baseline files (.ir.txt) will need updating since node type names appear in them.
• No codegen baselines (.codegen.cs, .codegen.html, .mappings.txt) should change.

ref: PR #12957 review comment #12957 (comment)