tests failed on armv7

Not sure what is at fault but I note that some test-cases are failing when test building 0.5.1 in Fedora 24 development (Rawhide) for armv7hl:

```
:
+ ./Setup test
Running 1 test suites...
Test suite test-cmark: RUNNING...

Cases: 6 Tried: 0 Errors: 0 Failures: 0
Cases: 6 Tried: 1 Errors: 0 Failures: 0
Cases: 6 Tried: 2 Errors: 0 Failures: 0
Cases: 6 Tried: 3 Errors: 0 Failures: 0
Cases: 6 Tried: 4 Errors: 0 Failures: 0

### Failure in: 4
expected: Node (Just (PosInfo {startLine = 1, startColumn = 1, endLine = 1, endColumn = 13})) DOCUMENT [Node (Just (PosInfo {startLine = 1, startColumn = 1, endLine = 1, endColumn = 13})) PARAGRAPH [Node Nothing DOCUMENT [],Node Nothing EMPH [Node Nothing DOCUMENT []]]]
but got: Node (Just (PosInfo {startLine = 1, startColumn = 1, endLine = 1, endColumn = 13})) DOCUMENT [Node (Just (PosInfo {startLine = 1, startColumn = 1, endLine = 1, endColumn = 13})) PARAGRAPH [Node Nothing (TEXT "Hello ") [],Node Nothing EMPH [Node Nothing (TEXT "world") []]]]

Cases: 6 Tried: 5 Errors: 0 Failures: 1

### Failure in: 5
expected: "> Hello\n> *world*\n"
but got: "> **\n"
Cases: 6 Tried: 6 Errors: 0 Failures: 2
Test suite test-cmark: FAIL
:
```

This is with ghc-7.8.4.