rust: backport explicit-tail-calls test skips for unsupported LLVM targets

diff --git a/meta/recipes-devtools/rust/files/0004-explicit-tail-calls-ignore-tests-on-unsupported-llvm.patch b/meta/recipes-devtools/rust/files/0004-explicit-tail-calls-ignore-tests-on-unsupported-llvm.patch
new file mode 100644
index 0000000000..a6b73cf326
--- /dev/null
+++ b/meta/recipes-devtools/rust/files/0004-explicit-tail-calls-ignore-tests-on-unsupported-llvm.patch
@@ -0,0 +1,96 @@ 
+Backport commits that disable failing tests on unsupported LLVM targets.
+
+Fixes LLVM ERROR: failed to perform tail call elimination on musttail marked calls.
+
+Upstream-Status: Backport [https://github.com/rust-lang/rust/commit/ded0aaba6ce257adf0b7e1fb6b702cad12328faf]
+
+Signed-off-by: Peter Tatrai <peter.tatrai.ext@siemens.com>
+
+---
+ src/tools/compiletest/src/directives/directive_names.rs |  3 ++
+ tests/ui/explicit-tail-calls/become-indirect-return.rs  | 21 +++++++++++++++++
+ tests/ui/explicit-tail-calls/indirect.rs               | 19 ++++++++++++++++
+ 3 files changed, 43 insertions(+)
+diff --git a/src/tools/compiletest/src/directives/directive_names.rs b/src/tools/compiletest/src/directives/directive_names.rs
+index 1234567..abcdefg 100644
+--- a/src/tools/compiletest/src/directives/directive_names.rs
++++ b/src/tools/compiletest/src/directives/directive_names.rs
+@@ -67,6 +67,7 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
+     "ignore-coverage-map",
+     "ignore-coverage-run",
+     "ignore-cross-compile",
++    "ignore-csky",
+     "ignore-eabi",
+     "ignore-elf",
+     "ignore-emscripten",
+@@ -91,6 +92,8 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[
+     "ignore-loongarch64",
+     "ignore-macabi",
+     "ignore-macos",
++    "ignore-mips",
++    "ignore-mips64",
+     "ignore-msp430",
+     "ignore-msvc",
+     "ignore-musl",
+diff --git a/tests/ui/explicit-tail-calls/become-indirect-return.rs b/tests/ui/explicit-tail-calls/become-indirect-return.rs
+index 1234567..abcdefg 100644
+--- a/tests/ui/explicit-tail-calls/become-indirect-return.rs
++++ b/tests/ui/explicit-tail-calls/become-indirect-return.rs
+@@ -2,6 +2,27 @@
+ //@ ignore-backends: gcc
+ //@ ignore-wasm 'tail-call' feature not enabled in target wasm32-wasip1
+ //@ ignore-cross-compile
++//
++// LLVM musttail support is incomplete for these targets.
++// See https://github.com/rust-lang/rust/issues/148748 for the target test matrix.
++// See https://github.com/llvm/llvm-project/issues/63214 for AIX and PowerPC.
++// See https://github.com/llvm/llvm-project/issues/57795 for MIPS and MIPS64.
++//@ ignore-aix
++//@ ignore-csky
++//@ ignore-mips
++//@ ignore-mips64
++//@ ignore-powerpc
++//@ ignore-powerpc64
++//
++// LLVM musttail support is lacking for sret lowering on these targets.
++// Returning `[u8; 24]` uses sret lowering here.
++// See https://github.com/llvm/llvm-project/issues/157814 for RISC-V.
++// See https://github.com/llvm/llvm-project/issues/168152 for LoongArch.
++// RISC-V fix: https://github.com/llvm/llvm-project/pull/185094, should be in LLVM 23.
++// LoongArch will likely be fixed with similar changes.
++//@ ignore-riscv64
++//@ ignore-loongarch32
++//@ ignore-loongarch64
+ #![expect(incomplete_features)]
+ #![feature(explicit_tail_calls)]
+ 
+diff --git a/tests/ui/explicit-tail-calls/indirect.rs b/tests/ui/explicit-tail-calls/indirect.rs
+index 1234567..abcdefg 100644
+--- a/tests/ui/explicit-tail-calls/indirect.rs
++++ b/tests/ui/explicit-tail-calls/indirect.rs
+@@ -2,7 +2,26 @@
+ //@ ignore-backends: gcc
+ //
+ //@ ignore-wasm
++//
++// LLVM musttail support is incomplete for these targets.
++// See https://github.com/rust-lang/rust/issues/148748 for the target test matrix.
++// See https://github.com/llvm/llvm-project/issues/63214 for AIX and PowerPC.
++// See https://github.com/llvm/llvm-project/issues/57795 for MIPS and MIPS64.
++//@ ignore-aix
++//@ ignore-csky
++//@ ignore-mips
++//@ ignore-mips64
++//@ ignore-powerpc
++//@ ignore-powerpc64
++//
++// LLVM musttail support is lacking for indirect arguments that do not fit in registers.
++// See https://github.com/llvm/llvm-project/issues/157814 for RISC-V.
++// See https://github.com/llvm/llvm-project/issues/168152 for LoongArch.
++// RISC-V fix: https://github.com/llvm/llvm-project/pull/185094, should be in LLVM 23.
++// LoongArch will likely be fixed with similar changes.
+ //@ ignore-riscv64
++//@ ignore-loongarch32
++//@ ignore-loongarch64
+ #![feature(explicit_tail_calls)]
+ #![expect(incomplete_features)]
diff --git a/meta/recipes-devtools/rust/rust-source.inc b/meta/recipes-devtools/rust/rust-source.inc
index 55c43ffd6d..094baba526 100644
--- a/meta/recipes-devtools/rust/rust-source.inc
+++ b/meta/recipes-devtools/rust/rust-source.inc
@@ -8,6 +8,7 @@  SRC_URI += "https://static.rust-lang.org/dist/rustc-${RUST_VERSION}-src.tar.xz;n
             file://0001-riscv32-Define-plain-syscalls-as-their-time64-varian.patch;patchdir=${RUSTSRC} \
             file://0002-Fix-rust-build-failure-with-unstable-options.patch;patchdir=${RUSTSRC} \
             file://0003-explicit-tail-calls-disable-two-tests.patch;patchdir=${RUSTSRC} \
+            file://0004-explicit-tail-calls-ignore-tests-on-unsupported-llvm.patch;patchdir=${RUSTSRC} \
 "
 SRC_URI[rust.sha256sum] = "b99ce16cdf0ecfc761b585ac84d131b46733465a02f8ecd0ff2de9713c62ee09"