Log Message:
Update libhighway to version 1.0.1

Pkgsrc changes:
Build shared libs.
Use gcc 8 and over to fix build.
Include devel/googletest in
buildlink3.mk since one of the
installed header files include
gtest/gtest.h .

Changes from changelog:

* Add Eq128, i64 Mul, unsigned->float ConvertTo
* Faster sort for few unique keys, more robust pivot selection
* Fix: floating-point generator for sort tests, Min/MaxOfLanes for i16
* Fix: avoid always_inline in debug, link atomic
* GCC warnings: string.h, maybe-uninitialized, ignored-attributes
* GCC warnings: preprocessor int overflow, spurious use-after-free/overflow
* Doc: <=HWY_AVX3, Full32/64/128, how to use generic-inl
* ABI change: 64-bit target values, more room for expansion
* Add CompressBlocksNot, CompressNot, Lt128Upper, Min/Max128Upper, TruncateTo
* Add HWY_SVE2_128 target
* Sort speedups especially for 128-bit
* Documentation clarifications
* Faster NEON CountTrue/FindFirstTrue/AllFalse/AllTrue
* Improved SVE codegen
* Fix u16x8 ConcatEven/Odd, SSSE3 i64 Lt
* MSVC 2017 workarounds
* Support for runtime dispatch on Arm/GCC/Linux