Have you ever analyzed the released Volt binary? It has symbols like this:

    000000010001dc30 g       0f SECT   01 0000 [.text] _f_1
    000000010001eba0 g       0f SECT   01 0000 [.text] _f_10
    00000001000219a0 g       0f SECT   01 0000 [.text] _f_100
    [...snip...]
    000000010004bae0 g       0f SECT   01 0000 [.text] _f_462
    000000010002a430 g       0f SECT   01 0000 [.text] _f_463
    0000000100037940 g       0f SECT   01 0000 [.text] _f_464
    000000010001f2f0 g       0f SECT   01 0000 [.text] _f_465
    0000000100020220 g       0f SECT   01 0000 [.text] _f_47
    0000000100020240 g       0f SECT   01 0000 [.text] _f_48
    00000001000202b0 g       0f SECT   01 0000 [.text] _f_49
    [...snip...]
    00000001000182a0 g       0f SECT   01 0000 [.text] _string_add
    000000010001a110 g       0f SECT   01 0000 [.text] _string_all_after
    000000010001a020 g       0f SECT   01 0000 [.text] _string_all_before
    000000010001a090 g       0f SECT   01 0000 [.text] _string_all_before_last
    0000000100019ef0 g       0f SECT   01 0000 [.text] _string_at
    0000000100018540 g       0f SECT   01 0000 [.text] _string_clone
    0000000100018aa0 g       0f SECT   01 0000 [.text] _string_contains
    0000000100018610 g       0f SECT   01 0000 [.text] _string_cstr
    0000000100019470 g       0f SECT   01 0000 [.text] _string_ends_with
    0000000100018b30 g       0f SECT   01 0000 [.text] _string_eq

While you can always mangle symbols, it is strange that i) every symbol is in public and ii) only some of them are mangled. Therefore I think the binary was probably produced by V's C transpiler, with some V standard library functions slapped on them.

(I had to rewrite the reply because I later realized that the binary was packed with UPX, I should have thoroughly inspected strings. Sorry for inconvenience.)