Make the --transformer CLI argument override the babelTransformerPath

Summary: D9070810 introduced a breaking change, making the `--transformer` CLI argument able to override the generic transformer instead of `babelTransformer`. Since we still have some scripts that assume `--transformer` is being used for overriding the babelTransformer path, we cannot do this breaking change yet, so this diff reverts the CLI handling to the old behaviour.

Reviewed By: jrwats

Differential Revision: D9550157

fbshipit-source-id: 8b4e26fcb5bca6e4b2f63b1e1a014bce23a31452

Author: rafeca

local-cli/bundle/buildBundle.js

@@ -44,10 +44,6 @@ async function buildBundle(
     sourceMapUrl = path.basename(sourceMapUrl);
   }
 
-  config.transformerPath = args.transformer
-    ? path.resolve(args.transformer)
-    : config.transformerPath;
-
   const requestOpts: RequestOptions = {
     entryFile: args.entryFile,
     sourceMapUrl,

local-cli/dependencies/dependencies.js

@@ -25,9 +25,6 @@ async function dependencies(argv, configPromise, args, packagerInstance) {
   }
 
   config.cacheStores = [];
-  if (args.transformer) {
-    config.transformer.babelTransformerPath = path.resolve(args.transformer);
-  }
 
   const relativePath = path.relative(
     config.projectRoot,