- Update _constraints to use 12GB RAM on x86_64

- Update to version 0.3.11
common:
* Reduced the default BLAS3_MEM_ALLOC_THRESHOLD (used as an upper
limit for placing temporary arrays on the stack) to be compatible
with a stack size of 1mb (as imposed by the JAVA runtime library)
* Added mixed-precision dot function SBDOT and utility functions
shstobf16, shdtobf16, sbf16tos and dbf16tod to convert between
single or double precision float arrays and bfloat16 arrays
* Fixed prototypes of LAPACK_?ggsvp and LAPACK_?ggsvd functions
in lapack.h
* Fixed underflow and rounding errors in LAPACK SLANV2 and DLANV2
(causing miscalculations in e.g. SHSEQR/DHSEQR, LAPACK issue #263)
* Fixed workspace calculation in LAPACK ?GELQ (LAPACK issue #415)
* Fixed several bugs in the LAPACK testsuite
* Improved performance of TRMM and TRSM for certain problem sizes
* Fixed infinite recursions and workspace miscalculations in ReLAPACK
* CMAKE builds no longer require pkg-config for creating the .pc file
* Makefile builds no longer misread NO_CBLAS=0 or NO_LAPACK=0 as
enabling these options
* Fixed detection of gfortran when invoked through an mpi wrapper
* Improve thread reinitialization performance with OpenMP after a fork
* Added support for building only the subset of the library required
for a particular precision by specifying BUILD_SINGLE, BUILD_DOUBLE
* Optional function name prefixes and suffixes are now correctly
reflected in the generated cblas.h
* Added CMAKE build support for the LAPACK and multithreading tests
power:
* Added optimized support for POWER10