[wasm] Small memory size crashes.

[wasm] Small memory size crashes.

This crashes with:

Fatal error in ../../src/assembler.cc, line 356
Check failed: new_size >= offset (1 vs. 3).

LOG=N
BUG=
R=gdeepti@chromium.org,titzer@chromium.org

[bradn, 2016-10-05 08:27:21]

bradnelson@google.com changed reviewers:
+ bradnelson@google.com

[titzer, 2016-10-05 08:30:00]

lgtm

[bradn, 2016-10-05 08:41:29]

No no, you misunderstand.
This crash, haven't fixed, was hoping gdeepti could take a look?

[titzer, 2016-10-05 08:48:27]

On 2016/10/05 08:41:29, bradn wrote:
> No no, you misunderstand.
> This crash, haven't fixed, was hoping gdeepti could take a look?

You can land the test and disable it in the status file, if you like.

[gdeepti, 2016-10-07 02:50:52]

https://codereview.chromium.org/2393083003/diff/1/test/mjsunit/wasm/module-me...
File test/mjsunit/wasm/module-memory.js (right):

https://codereview.chromium.org/2393083003/diff/1/test/mjsunit/wasm/module-me...
test/mjsunit/wasm/module-memory.js:47: var buffer = new ArrayBuffer(1);
Following up from offline discussions, this test should not pass because the 
 - Memory is not aligned to page size. 
 - Imported memory should be in the form of WebAssembly.Memory object

I will follow up to add checks in Instantiate/GrowMemory/MemorySize methods for
the memory to be aligned to page size.