[AsmPrinter] De-capitalize all AsmPrinter::Emit* but EmitInstruction

Similar to rL328848.
diff --git a/llvm/docs/GarbageCollection.rst b/llvm/docs/GarbageCollection.rst
index 8c6b046..ade944b 100644
--- a/llvm/docs/GarbageCollection.rst
+++ b/llvm/docs/GarbageCollection.rst
@@ -958,7 +958,7 @@
       // } __gcmap_<FUNCTIONNAME>;
 
       // Align to address width.
-      AP.EmitAlignment(IntPtrSize == 4 ? 2 : 3);
+      AP.emitAlignment(IntPtrSize == 4 ? 2 : 3);
 
       // Emit PointCount.
       OS.AddComment("safe point count");