https://bugs.gentoo.org/832700
https://github.com/oneapi-src/oneTBB/commit/6a15b64093c51ddc00bdf4a6b49d4bbec1574a12

From: Rui Ueyama <rui314@gmail.com>
Date: Fri, 4 Feb 2022 19:32:11 +0900
Subject: [PATCH] Make tbb compile with musl libc (#748)

TBB resumable tasks are implemented using getcontext() and setcontext()
on Unix-like systems. These functions are deprecated in the recent
versions of POSIX and may not exist. musl libc does not provide these
functions.

There's unfortunately no way to detect musl (musl intentionally do not
define macros like `__MUSL__`), so __TBB_RESUMABLE_TASKS is defined if
`__GLIBC__`. glibc-compatible libc's such as uClibc defines `__GLIBC__`,
so it should work as a catch-all condition.

Signed-off-by: Rui Ueyama <ruiu@cs.stanford.edu>
--- a/include/oneapi/tbb/detail/_config.h
+++ b/include/oneapi/tbb/detail/_config.h
@@ -268,7 +268,7 @@
     #define __TBB_CPP20_COMPARISONS_PRESENT __TBB_CPP20_PRESENT
 #endif
 
-#define __TBB_RESUMABLE_TASKS                           (!__TBB_WIN8UI_SUPPORT && !__ANDROID__ && !__QNXNTO__)
+#define __TBB_RESUMABLE_TASKS                           (!__TBB_WIN8UI_SUPPORT && !__ANDROID__ && !__QNXNTO__ && (!__linux__ || __GLIBC__))
 
 /* This macro marks incomplete code or comments describing ideas which are considered for the future.
  * See also for plain comment with TODO and FIXME marks for small improvement opportunities.