Revert "Merge branch 'do-optional-semicolon' of https://github.com/sebmck/acorn"

This reverts commit c526814896711439b89f613fe0412aad4c1730a8, reversing
changes made to e7fea263dac65061941a4cee25c7a84c4e50c8bf.

acorn.js

@@ -2027,7 +2027,7 @@
     labels.pop();
     expect(_while);
     node.test = parseParenExpression();
-    eat(_semi);
+    semicolon();
     return finishNode(node, "DoWhileStatement");
   }
   

test/tests.js

@@ -17911,49 +17911,6 @@ test("do keep(); while (true);", {
   }
 });
 
-test("do {} while (false) foo();", {
-  type: "Program",
-  start: 0,
-  end: 26,
-  body: [
-    {
-      type: "DoWhileStatement",
-      start: 0,
-      end: 19,
-      body: {
-        type: "BlockStatement",
-        start: 3,
-        end: 5,
-        body: []
-      },
-      test: {
-        type: "Literal",
-        start: 13,
-        end: 18,
-        value: false,
-        raw: "false"
-      }
-    },
-    {
-      type: "ExpressionStatement",
-      start: 20,
-      end: 26,
-      expression: {
-        type: "CallExpression",
-        start: 20,
-        end: 25,
-        callee: {
-          type: "Identifier",
-          start: 20,
-          end: 23,
-          name: "foo"
-        },
-        arguments: []
-      }
-    }
-  ]
-});
-
 test("do { x++; y--; } while (x < 10)", {
   type: "Program",
   body: [