Make libcore compile with BoringSSL.

NativeBN_putULongInt was cleaned up because of a slightly worrying mix
of signed and unsigned ints, and because of an unneeded preprocessor
test. However, as I look down the rest of the file, there's a lot of it
but I didn't get to fixing it all up.

Bug: 17409664
Change-Id: If0adde83bebf04e7e3be163c1b30ebef75a67d05
Signed-off-by: Adam Langley <agl@google.com>
Revert "Implements some StrictMath functions for improved performance."

This reverts commit 165e2b4075dadb99afc0856ab3c698809a6355a2.
Merge "Revert "Implements some StrictMath functions for improved performance.""
Tidy up DecimalFormatTest

The intent is to clean up the code to make it more obvious
where things are failing and why. The names of the tests now
better reflect their purpose and the code is reformatted.

Some tests have been merged where they overlapped and some
have been split.

Change-Id: Ic31e2062c2682b6b3ac349c8fb76c9b9809e2150
Revert "Make parameter name match comments for sdk build."

This reverts commit 716ec14a8b68157293c33b3bdd79a6ecc57f579b.
Merge "Revert "Make parameter name match comments for sdk build.""
Merge "Make libcore compile with BoringSSL."
Merge "Tidy up DecimalFormatTest"