If this attribute is given and all modules in the linkage unit have this
attribute, this value may be omitted from the dynamic symbol table. This
is set on constant linkonce_odr globals whose addresses are insignificant
within the module. Because such globals must be defined in each linkage unit
that uses them, a valid program would not be able to observe the absence of
the symbol unless its address is significant.
Part of the fix for PR27553.