Upgrade OpenBLAS to 0.2.20:

• Fixed several thread race and locking bugs
• Fixed default LAPACK optimization level
• Updated LAPACK to 3.7.0
• Power
  • Optimizations for Power9
  • Fixed several Power8 assembly bugs
• ARM
  • New optimized Vulcan and ThunderX2T99 targets
  • Support for ARMV7 SOFT_FP ABI (make ARM_SOFTFP_ABI=1)
  • Detect all cpu cores including offline ones
  • Fix compilation with CLANG
• MIPS
  • Fixed several threading issues
  • Fix compilation with CLANG
• x86_64
  • Detect Intel Bay Trail and Apollo Lake
  • Detect Intel Sky Lake and Kaby Lake
  • Detect Intel Knights Landing
  • Detect AMD A8, A10, A12 and Ryzen
  • Fix cmake builds for Haswell and related cpus
  • Fix building for Sandybridge with CLANG 3.9

Pet portlint (USES vs. USE)

PR: 221633
Submitted by: truckman
Approved by: phd_kimberlite@yahoo.co.jp (maintainer)