[Docs] Fix sphinx warning.
Fix sphinx warning over an ambigious reference.
diff --git a/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl03.rst b/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl03.rst
index 9b6df01..c172477 100644
--- a/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl03.rst
+++ b/llvm/docs/tutorial/MyFirstLanguageFrontend/LangImpl03.rst
@@ -196,7 +196,7 @@
suffix. Local value names for instructions are purely optional, but it
makes it much easier to read the IR dumps.
-:doc:`LLVM instructions <LangRef>` are constrained by strict
+:doc:`LLVM instructions <../../LangRef.html#instruction-reference>`_ are constrained by strict
rules: for example, the Left and Right operators of an `add
instruction <../../LangRef.html#add-instruction>`_ must have the same type, and the
result type of the add must match the operand types. Because all values