Update emphasis rule to the latest CommonMark spec

lib/rules_inline/emphasis.js

@@ -21,8 +21,6 @@ function parseStart(state, start) {
 
   lastChar = state.pending.length !== 0 ? state.pending.charCodeAt(state.pending.length - 1) : -1;
 
-  if (lastChar === marker) { return -1; }
-
   while (pos < max && state.src.charCodeAt(pos) === marker) { pos++; }
   if (pos >= max) { return -1; }
   count = pos - start;
@@ -103,7 +101,6 @@ module.exports = function emphasis(state/*, silent*/) {
       oldCount,
       newCount,
       stack,
-      breakOutOfOuterLoop,
       max = state.posMax,
       start = state.pos,
       haveLiteralAsterisk,
@@ -142,20 +139,8 @@ module.exports = function emphasis(state/*, silent*/) {
         newCount = count;
 
         while (oldCount !== newCount) {
-          if (oldCount === 3) {
-            // e.g. `***foo*`
-            stack.push(3 - newCount);
-            break;
-          }
-
           if (newCount < oldCount) {
-            // assert(oldCount == 2 && newCount == 1)
-            // i.e. `**foo* bar*`
-            // not valid for now, but might be in the future
-
-            // eslint is misconfigured, so it doesn't accept "break MAIN;"
-            // here is a crappy workaround
-            breakOutOfOuterLoop = true;
+            stack.push(oldCount - newCount);
             break;
           }
 
@@ -167,8 +152,6 @@ module.exports = function emphasis(state/*, silent*/) {
           oldCount = stack.pop();
         }
 
-        if (breakOutOfOuterLoop) { break; }
-
         if (stack.length === 0) {
           startCount = oldCount;
           found = true;