Merge branch 'amd' into rt

Details:
- Merged contributions made by AMD via 'amd' branch (see summary below).
  Special thanks to AMD for their contributions to-date, especially with
  regard to intrinsic- and assembly-based kernels.
- Added column storage output cases to microkernels in
  bli_gemm_zen_asm_d6x8.c and bli_gemmtrsm_l_zen_asm_d6x8.c. Even with
  the extra cost of transposing the microtile in registers, this is
  much faster than using the general storage case when the underlying
  matrix is column-stored.
- Added s and d assembly-based zen gemmtrsm_u microkernel (including
  column storage optimization mentioned above).
- Updated zen sub-configuration to reflect presence of new native
  kernels.
- Temporarily reverted zen sub-configuration's level-3 cache blocksizes
  to smaller haswell values.
- Temporarily disabled small matrix handling for zen configuration
  family in config/zen/bli_family_zen.h.
- Updated zen CFLAGS according to changes in 1e4365b.
- Updated haswell microkernels such that:
  - only one vzeroupper instruction is called prior to returning
  - movapd/movupd are used in leiu of movaps/movups for double-real
    microkernels. (Note that single-real microkernels still use
    movaps/movups.)
- Added kernel prototypes to kernels/zen/bli_kernels_zen.h, which is
  now included via frame/include/bli_arch_config.h.
- Minor updates to bli_amaxv_ref.c (and to inlined "test" implementation
  in testsuite/src/test_amaxv.c).
- Added early return for alpha == 0 in bli_dotxv_ref.c.
- Integrated changes from f07b176, including a fix for undefined
  behavior when executing the 1m method under certain conditions.
- Updated config_registry; no longer need haswell kernels for zen
  sub-configuration.
- Tweaked marginal and pass thresholds for dotxf.
- Reformatted level-1v, -1f, and -3 amd kernels and inserted additional
  comments.
- Updated LICENSE file to explicitly mention that parts are copyright
  UT-Austin and AMD.
- Added AMD copyright to header templates in build/templates.

Summary of previous changes from 'amd' branch.
- Added s and d assembly-based zen gemm microkernels (d6x8 and d8x6) and
  s and d assembly-based zen gemmtrsm_l microkernels (d6x8).
- Added s and d intrinsics-based zen kernels for amaxv, axpyv, dotv, dotxv,
  and scalv, with extra-unrolling variants for axpyv and scalv.
- Added a small matrix handler to bli_gemm_front(), with the handler
  implemented in kernels/zen/3/bli_gemm_small_matrix.c.
- Added additional logic to sumsqv that first attempts to compute the
  sum of the squares via dotv(). If there is a floating-point exception
  (FE_OVERFLOW), then the previous (numerically conservative) code is
  used; otherwise, the result of dotv() is square-rooted and stored as
  the result. This new implementation is only enabled when FE_OVERFLOW
  is #defined. If the macro is not #defined, then the previous
  implementation is used.
- Added axpyv and dotv standalone test drivers to test directory.
- Added zen support to old cpuid_x86.c driver in build/auto-detect/old.
- Added thread-local and __attribute__-related macros to bli_macro_defs.h.

frame/include/bli_arch_config.h

@@ -214,9 +214,9 @@ CNTX_INIT_PROTS( generic )
 
 // -- AMD64 architectures --
 
-//#ifdef BLIS_KERNELS_ZEN
-//#include "bli_kernels_zen.h"
-//#endif
+#ifdef BLIS_KERNELS_ZEN
+#include "bli_kernels_zen.h"
+#endif
 //#ifdef BLIS_KERNELS_EXCAVATOR
 //#include "bli_kernels_excavator.h"
 //#endif