Update to upstream version 1.8.0

Detailed log:

• Update to upstream version 1.8.0
• New default OPTION TESTS: Build with regression tests
• Now choice possible between different math libs: SYSLIBM (-lm) OPENLIBM (math/openlibm) APPLIBM (bundled), default

PR: 218612
Submitted by: cs@innolan.dk (maintainer)
MFH: 2017Q2