Add support for import typeof, fixes #1975

plugins/flow.js

@@ -791,16 +791,15 @@ acorn.plugins.flow = function (instance) {
 
   instance.extend("parseImportSpecifiers", function (inner) {
     return function (node) {
-      node.isType = false
-      if (this.isContextual("type")) {
-        var start = this.markPosition()
-        var typeId = this.parseIdent()
-        if ((this.type === tt.name && this.value !== "from") || this.type === tt.braceL || this.type === tt.star) {
-          node.isType = true
-        } else {
-          node.specifiers.push(this.parseImportSpecifierDefault(typeId, start))
-          if (this.isContextual("from")) return
-          this.eat(tt.comma)
+      node.importKind = "value"
+      var kind =
+        (this.type === tt._typeof ? "typeof" :
+        (this.isContextual("type") ? "type" : null))
+      if (kind) {
+        var lh = this.lookahead()
+        if ((lh.type === tt.name && lh.value !== "from") || lh.type === tt.braceL || lh.type === tt.star) {
+          this.next()
+          node.importKind = kind
         }
       }
       inner.call(this, node)