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

[Alexey Bader via cfe-commits]

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@@ -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
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bader wrote:

Do I get it right that prefix is unique for each split rather than per `clang-sycl-linker` invocation? If so, using `_N` notation loses its meaning. Existing file suffix avoids collision between splits. Adding unique suffix solves this problem as well.

Please, drop `_N` suffix.

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