[llvm] [Support] Vendor rpmalloc in-tree and use it for the Windows 64-bit release (PR #91862)

[Chris B via llvm-commits]

llvm-beanz wrote:

@mjansson, as the original author of much of this code can you please confirm on this thread that you are consenting to it being contributed under the LLVM licensing terms? The current licensing terms are documented in the developer policy here: https://github.com/llvm/llvm-project/blob/main/llvm/docs/DeveloperPolicy.rst#copyright-license-and-patents.

At the moment this requires all code to be licensed under both the new Apache w/ LLVM license and the legacy NCSA license.

There is a plan to only require the new license in the future (see: https://discourse.llvm.org/t/relicensing-next-step-dropping-requirement-to-contribute-also-under-the-legacy-license/78351), but for now all code contributed must be available under either license.

Thank you!

https://github.com/llvm/llvm-project/pull/91862