GCC never returns 1 when you call the inline function with a string
constant or ...
Because rb_str_new and familiy take string constants, it was a bad idea
for them to contain RB_CONSTANT_P. We should instead do so in
corresponding macros. [ruby-core:98212]
Added by shyouhei (Shyouhei Urabe) about 5 years ago
rb_str_new: hoist RB_CONSTANT_P out of function
https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html says:
Because rb_str_new and familiy take string constants, it was a bad idea
for them to contain RB_CONSTANT_P. We should instead do so in
corresponding macros. [ruby-core:98212]