Compilation hangs on NPB/ua/mason.c

[beowulf]

Compiling NPB3.3-SER-C-FLAT/ua/mason.c hangs without any progress for minutes.

Versions:

• Compiler: master / ce78b7a93f776d4a55d9dbccc565699571d2fa24
• NPB: make-popcorn-explicit / 9f4662d9107993d2ca2322e55519801aa0f5387c

[beowulf]

Heard from @rlyerly that there is a state explosion in NPB ua while tracking live values, which is subtle to handle right away.

[rlyerly]

This has been fixed in commit 8c4b9c38c7f3896c4bc7dbda87a3731f81fa9b5b