Fix compilation on macOS with GCC.

[Jhuighuy]

Description

This PR fixes compilation on macOS with GCC (broken in 2022.0, worked fine in 2021.13). What's changed:

• GCC toolchain code assumed that the assembler is always GAS. This may not always be the case, for example, on macOS GCC uses LLVM assembler.
• Changed __TBB_WAITPKG_INTRINSICS_PRESENT: it is now always defined to true on macOS and GCC (always fresh LLVM assembler, so the intrinsic is always present).
• Changed a workaround for -Wdeprecated-declarations in co_context.h: the warning was disabled with a Clang-specific pragma, replaced with Clang-compatible GCC version.

With this changes it is possible to compile and run all tests:

$ mkdir build
$ cd build
$ CXX=g++-14 cmake .. -DBUILD_SHARED_LIBS=NO
$ make
$ make test

Compilation with BUILD_SHARED_LIBS=YES still fails: the linker cannot find a vtable for detail::r1::unsafe_wait. This should be fixed separately.

Fixes #1556

Type of change

• bug fix - change that fixes an issue
• new feature - change that adds functionality
• tests - change in tests
• infrastructure - change in infrastructure and CI
• documentation - documentation update

Tests

• added - required for new features and some bug fixes
• not needed

Documentation

• updated in # - add PR number
• needs to be updated
• not needed

Breaks backward compatibility

• Yes
• No
• Unknown

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Other information

[Jhuighuy]

Updated copyright years.