codegen assertion in BitIntegers

[JeffBezanson]

With #34287 running ]test BitIntegers:

julia: /home/jeff/src/julia/src/cgutils.cpp:514: unsigned int convert_struct_offset(llvm::Type*, unsigned int): Assertion `SL->getElementOffset(idx) == byte_offset' failed.

signal (6): Aborted
in expression starting at /home/jeff/.julia/packages/BitIntegers/4QmBA/test/runtests.jl:333
gsignal at /lib/x86_64-linux-gnu/libc.so.6 (unknown line)
abort at /lib/x86_64-linux-gnu/libc.so.6 (unknown line)
unknown function (ip: 0x7f5b6a6b2bf5)
__assert_fail at /lib/x86_64-linux-gnu/libc.so.6 (unknown line)
convert_struct_offset at /home/jeff/src/julia/src/cgutils.cpp:514
convert_struct_offset at /home/jeff/src/julia/src/cgutils.cpp:527 [inlined]
convert_struct_offset at /home/jeff/src/julia/src/cgutils.cpp:520 [inlined]
emit_struct_gep at /home/jeff/src/julia/src/cgutils.cpp:525
emit_getfield_knownidx at /home/jeff/src/julia/src/cgutils.cpp:1672
emit_builtin_call at /home/jeff/src/julia/src/codegen.cpp:2872

[vtjnash]

Duplicate of #32414

[rfourquet]

The fix for the duplicate doesn't seem to fix this issue, so re-opening. Sorry if I messed my testing and got this wrong.

[rfourquet]

Minimal repro:

using BitIntegers
BitIntegers.@define_integers 24
Base.checked_usub_int(UInt24(3), UInt24(3)) == (UInt24(0), false)

[rfourquet]

The minimal repro above seems to have been fixed in 1.6. But I found another "Internal error" in today's master (d6c092d):

julia> using BitIntegers

julia> BitIntegers.@define_integers 24; x = UInt24(0);

julia> x
Internal error: encountered unexpected error in runtime:
MethodError(f=Main.UInt24, args=(0,), world=0x0000000000001133)
jl_method_error_bare at /local/src/julia/src/gf.c:1818
jl_method_error at /local/src/julia/src/gf.c:1836
jl_lookup_generic_ at /local/src/julia/src/gf.c:2406 [inlined]
jl_apply_generic at /local/src/julia/src/gf.c:2421
convert at ./number.jl:7
zero at ./number.jl:292
_jl_invoke at /local/src/julia/src/gf.c:2243 [inlined]
jl_apply_generic at /local/src/julia/src/gf.c:2425
[...]

It's a relatively recent error which was not there in d524f21 (81 days old master).
The error happens in show, defined as follows:

julia> print(stdout, "0x", string(x, pad = sizeof(x)<<1, base = 16))
0x000000
julia> f(x) = print(stdout, "0x", string(x, pad = sizeof(x)<<1, base = 16)); f(x)
Internal error: encountered unexpected error in runtime:
[...]
unknown function (ip: 0x401089)
0x000000

(note it still prints at the end).