No bug - Update boundsCheckLimit comment to match the code, and fix some typos. DONTBUILD

MozReview-Commit-ID: KPEMqOOKSmP

--HG--
extra : rebase_source : 7c6b52c65c0287d85a9793f93c7a0cba34d6413a

js/src/vm/ArrayBufferObject.cpp

@@ -443,12 +443,12 @@ ArrayBufferObject::changeContents(JSContext* cx, BufferContents newContents,
  * The linear heap in Wasm is an mmaped array buffer. Several
  * constants manage its lifetime:
  *
- *  - length - the wasm-visible current length of the buffer. Acesses in the
- *    range [0, length] succeed. May only increase
+ *  - length - the wasm-visible current length of the buffer. Accesses in the
+ *    range [0, length] succeed. May only increase.
  *
  *  - boundsCheckLimit - when !WASM_HUGE_MEMORY, the size against which we
  *    perform bounds checks. It is always a constant offset smaller than
- *    mappedSize. Currently that constant offset is 0.
+ *    mappedSize. Currently that constant offset is 64k (wasm::GuardSize).
  *
  *  - max - the optional declared limit on how much length can grow.
  *
@@ -456,10 +456,10 @@ ArrayBufferObject::changeContents(JSContext* cx, BufferContents newContents,
  *    [0, mappedSize] will either succeed, or be handled by the wasm signal
  *    handlers.
  *
- * The below diagram shows the layout of the wams heap. The wasm-visible
+ * The below diagram shows the layout of the wasm heap. The wasm-visible
  * portion of the heap starts at 0. There is one extra page prior to the
  * start of the wasm heap which contains the WasmArrayRawBuffer struct at
- * its end. (i.e. right before the start of the WASM heap).
+ * its end (i.e. right before the start of the WASM heap).
  *
  *  WasmArrayRawBuffer
  *      \    ArrayBufferObject::dataPointer()