TBR: i#2069: remove over-zealous assert on app munmap overlap

Commit log for first patchset:
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i#2069: remove over-zealous assert on app munmap overlap

Removes an assert on an app munmap overlapping allocated space as this
happensin real apps and furthermore DR should not assert on failing or nop
app syscalls.

Fixes #2069
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[bruening, 2016-12-01 22:03:45]

Committed as
https://github.com/DynamoRIO/dynamorio/commit/3e12b156b30f47cf2ca86599b0a55bb...

Final commit log: 
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i#2069: remove over-zealous assert on app munmap overlap

Removes an assert on an app munmap overlapping allocated space as this
happensin real apps and furthermore DR should not assert on failing or nop
app syscalls.

Fixes #2069

Review-URL: https://codereview.appspot.com/315110043
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