Fix BuilderTransform.cpp buildFialBlock typo

I was poking around this file looking into #85837 and noticed this typo...

Author: ultramiraculous

lib/Sema/BuilderTransform.cpp

@@ -363,7 +363,7 @@ class ResultBuilderTransform
     } else {
       Expr *buildBlockResult = buildBlockVarRef.get();
       // Otherwise, it's a top-level brace and we need to synthesize
-      // a call to `buildFialBlock` if supported.
+      // a call to `buildFinalBlock` if supported.
       if (builder.supports(ctx.Id_buildFinalResult, {Identifier()})) {
         buildBlockResult =
             builder.buildCall(resultLoc, ctx.Id_buildFinalResult,