[lldb][CMake] Don't condition libc++ requirement on LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS (#175955)
This reverts:
```
commit 78769d51c6b183b6d88fbd1ef825fff7cf3aad21
Author: Adrian Prantl <aprantl@apple.com>
Date: Tue Nov 4 08:29:47 2025 -0800
[LLDB] Don't check for libcxx if LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS is off
```
This was needed as an [escape hatch for our ASAN
bot](https://github.com/llvm/llvm-zorg/commit/e78725d94b72227e4e524e9b76900ed197791419)
because we couldn't build libc++ on it. Ever since
https://github.com/llvm/llvm-zorg/pull/702 we can.
Most people wouldn't know to `LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS`
when building LLDB. Which means they'd never know to build libc++, and
thus would have worse test-coverage for our data-formatters.
If we really want such an escape hatch, we might want to name it
something more explicit like `RELAX_DARWIN_LIBCXX_TEST_REQUIREMENTS`.
An alternative is to enable `LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS` by
default.
Welcome to the LLVM project!
This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.
The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.
C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.
Other components include: the libc++ C++ standard library, the LLD linker, and more.
Consult the Getting Started with LLVM page for information on building and running LLVM.
For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.
Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.
The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.