build: remove unused REFNAME macro from SANITY_CHECK
REFNAME was defined as a preprocessor macro (-DREFNAME=$(*F)f$(BU)) but
appears to have never been consumed by any source code. The SANITY_CHECK
feature uses common_reference.h which has its own independent mechanism
via BLASFUNC_REF macros with hardcoded REF_BU=f.
For context, REFNAME was imported with GotoBLAS2 in 2011 but became dead
code when the unit test framework added common_reference.h with its own
naming scheme. The CMake version also had a broken $(*F) reference that
could never work, but this was also moot since the macro was unused.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Fix LIBNAMESUFFIX handling in CMake and update documentation
- Fix cmake/system.cmake: LIBPREFIX was incorrectly overwritten when
LIBNAMESUFFIX was defined, losing both "lib" prefix and "openblas"
- Fix Makefile.rule docs: typo used LIBNAMESUFFIX instead of LIBNAMEPREFIX
- Fix Makefile.rule docs: removed misleading underscores from examples
- Fix docs/build_system.md: removed incorrect claim about automatic
underscore separator
The implementation does not add an underscore before the suffix - users
who want a separator should include it in their LIBNAMESUFFIX value
(e.g., LIBNAMESUFFIX=_omp).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>