chore: fix "isRuntimeBultinType" typo (#9307)

Author: simon-dima

src/Lean/Compiler/LCNF/MonoTypes.lean

@@ -52,7 +52,7 @@ def hasTrivialStructure? (declName : Name) : CoreM (Option TrivialStructureInfo)
     trivialStructureInfoExt.insert declName info?
     return info?
 where fillCache : CoreM (Option TrivialStructureInfo) := do
-  if isRuntimeBultinType declName then return none
+  if isRuntimeBuiltinType declName then return none
   let .inductInfo info ← getConstInfo declName | return none
   if info.isUnsafe || info.isRec then return none
   let [ctorName] := info.ctors | return none

src/Lean/Compiler/LCNF/ToLCNF.lean

@@ -671,7 +671,7 @@ where
 
   visitProjFn (projInfo : ProjectionFunctionInfo) (e : Expr) : M Arg := do
     let typeName := projInfo.ctorName.getPrefix
-    if isRuntimeBultinType typeName then
+    if isRuntimeBuiltinType typeName then
       let numArgs := e.getAppNumArgs
       let arity := projInfo.numParams + 1
       if numArgs < arity then

src/Lean/Compiler/LCNF/Util.lean

@@ -89,7 +89,7 @@ def builtinRuntimeTypes : Array Name := #[
 /--
 Return `true` iff `declName` is the name of a type with builtin support in the runtime.
 -/
-def isRuntimeBultinType (declName : Name) : Bool :=
+def isRuntimeBuiltinType (declName : Name) : Bool :=
   builtinRuntimeTypes.contains declName
 
 end Lean.Compiler.LCNF