cmake HAVE_LOG2 examples

mongodb/mongo-bi-connector-odbc-driver configure.cmake :538 

CHECK_SYMBOL_EXISTS(log2  math.h HAVE_LOG2)

alibaba/AliSQL configure.cmake :682 

CHECK_SYMBOL_EXISTS(log2  math.h HAVE_LOG2)

arkdb/arkproxy configure.cmake :467 

CHECK_SYMBOL_EXISTS(log2  math.h HAVE_LOG2)

alibaba/AliSQLBackup configure.cmake :597 

CHECK_SYMBOL_EXISTS(log2  math.h HAVE_LOG2)

KhronosGroup/SPIRV-LLVM cmake/config-ix.cmake :146 

check_symbol_exists(log2 math.h HAVE_LOG2)