[clang] [clang-sycl-linker] Make JIT/AOT temp files land relative to cwd with unique names (PR #224506)

[Ayan Khan via cfe-commits]

================
@@ -47,8 +47,8 @@
 ; SPLIT-SRC-NEXT: sycl-module-split: input: [[LLVMLINKOUT]].bc, mode: translation_unit
 ; SPLIT-SRC-NEXT: [[S0:.*]].bc [kernel_b kernel_c ]
 ; SPLIT-SRC-NEXT: [[S1:.*]].bc [kernel_a ]
-; SPLIT-SRC-NEXT: LLVM backend: input: [[S0]].bc, output: {{.*}}_0.spv
-; SPLIT-SRC-NEXT: LLVM backend: input: [[S1]].bc, output: {{.*}}_1.spv
+; SPLIT-SRC-NEXT: LLVM backend: input: [[S0]].bc, output: {{.*}}_0{{.*}}.spv
+; SPLIT-SRC-NEXT: LLVM backend: input: [[S1]].bc, output: {{.*}}_1{{.*}}.spv
----------------
ThunderKhan wrote:

I think the distinction makes sense. If _N is intended to identify the split consistently for -save-temps debugging, then it has a purpose separate from the unique suffix, which is there to prevent cross-invocation collisions.

One thing I’m curious about is whether that split index is guaranteed to remain stable for a given kernel across different invocations, or whether it can change depending on module/symbol ordering. If it is intended to be stable, it might be worth making that invariant explicit in the test or comments.

https://github.com/llvm/llvm-project/pull/224506