Remove libstdc++ dependency from NativeAOT

[am11]

Fixes #76655.

[EgorBo]

nice, I'm just curious - does it lead to a smaller binary size?

[eerhardt]

does it lead to a smaller binary size?

I don't know about the binary size (I haven't tested it), but it leads to a smaller container size because you don't need to install libstdc++ as a dependency. Here's the "docker inspect" of a small example NativeAOT app built on alpine:

Note that the libstdc++ dependency almost doubles the starting image size.

[am11]

nice, I'm just curious - does it lead to a smaller binary size?

Yes and no.

linux-x64: yes (-15kb). crossgen2's native binary size went from 45249216 -> 45233888 bytes.
osx-arm64: no (+1.4kb). crossgen2's native binary size went from 67941062 -> 67942550 bytes.

If we convert it to pure C, then it will get slimmer on both. Right now, compiler is baking in some code in -nostdlib / -nostdlib++ mode for C++ sources and it is bulkier than pure C (and what can be achieved with -ffreestanding).

[jkotas]

Looks great to me!

@AaronRobinsonMSFT Any other feedback?

cc @dotnet/gc for awareness. This contains some minor changes in GC/EE interface contract. These changes do not break binary compatibility - newer standalone gc builds should continue to work with older runtimes, just like before.

[mangod9]

thx!

[jkotas]

Failure is dotnet/arcade#11239

[am11]

@EgorBo, crossgen2 binary size with final changes:

macOS (arm64): +272 bytes
Linux (x64): -10608 bytes