Rename all proposal plugins to -proposal- from -transform- (#6570)

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-rest/with-array-rest/actual.js

@@ -0,0 +1,8 @@
+let {
+  a: [b, ...arrayRest],
+  c = function(...functionRest){},
+  ...objectRest
+} = {
+  a: [1, 2, 3, 4],
+  d: "oyez"
+};

packages/babel-plugin-proposal-object-rest-spread/test/fixtures/object-rest/with-array-rest/expected.js

@@ -0,0 +1,9 @@
+let _a$d = {
+  a: [1, 2, 3, 4],
+  d: "oyez"
+},
+    {
+  a: [b, ...arrayRest],
+  c = function (...functionRest) {}
+} = _a$d,
+    objectRest = babelHelpers.objectWithoutProperties(_a$d, ["a", "c"]);