Allow an optional suffix uniquifier string for mapping sybmol

riscv-elf.adoc

@@ -785,6 +785,9 @@ without ISA string means using ISA configuration from ELF attribute.
 Format and rule of the optional ISA string is same as Tag_RISCV_arch, must
 having explicit version, more detailed rule please refer to <<Attributes>>.
 
+Mapping sybmol name is allowed with an optional suffix uniquifier string start
+with a dot(`.`), e.g. `$d.yyyy`, `$x.zzzz` or `$xrv64imafdc.abc`.
+
 NOTE: The use case for mapping symbol for instruction(`$x`) with ISA information is
 used with ifunc, e.g. library are built with `rv64gc`, but few functions
 like memcpy provide two version, one built with `rv64gc`, and one built with