longlong.h for RISCV should define count_leading_zeros and
count_trailing_zeros and COUNT_LEADING_ZEROS_0 when ZBB is enabled.
The following patch patch fixes the bug reported in,
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110181
The divdi3 on riscv32 with zbb extension generates __clz_tab
instead of genearating __builtin_clzll/__builtin_clz which is
not efficient since lookup table is emitted.
Updating longlong.h to use this __builtin_clzll/__builtin_clz
generates optimized code for the instruction.
PR target/110181
include/ChangeLog
* longlong.h [__riscv] (count_leading_zeros): Define.
[__riscv] (count_trailing_zeros): Likewise.
[__riscv] (COUNT_LEADING_ZEROS_0): Likewise.
e08ef05e4d