[SYCL] Fix TCAndArchs leaking across offload kinds in BuildOffloadingActions (#22463)

TCAndArchs was declared outside the per-kind loop but only cleared
inside it after the bug was introduced by ccdf2c6. Without the clear,
entries from prior kinds (e.g. OpenMP's spir64 TC) accumulated and were
incorrectly used when processing subsequent kinds (SYCL), causing SYCL
device actions to pick up the wrong toolchain triple.

CMPLRLLVM-76332

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: wenju-he

clang/lib/Driver/Driver.cpp

@@ -7936,6 +7936,7 @@ Driver::BuildOffloadingActions(Compilation &C, llvm::opt::DerivedArgList &Args,
   for (Action::OffloadKind Kind : OffloadKinds) {
     SmallVector<const ToolChain *, 2> ToolChains;
     ActionList DeviceActions;
+    TCAndArchs.clear();
 
     auto TCRange = C.getOffloadToolChains(Kind);
     for (auto TI = TCRange.first, TE = TCRange.second; TI != TE; ++TI)

clang/test/Driver/sycl-offload-new-driver.cpp

@@ -280,3 +280,20 @@
 // RUN:          -fsycl-link %s 2>&1 \
 // RUN:  | FileCheck -check-prefix CHECK_SYCL_DEVICE_LINKING %s
 // CHECK_SYCL_DEVICE_LINKING: clang-linker-wrapper{{.*}} "--sycl-device-link"
+
+/// Check that SYCL device uses its own toolchain triple when combined with
+/// OpenMP offloading. Regression test: TCAndArchs must be cleared per offload
+/// kind to prevent OpenMP's TC leaking into SYCL's device phases.
+// RUN: %clang -ccc-print-phases --target=x86_64-unknown-linux-gnu -fsycl \
+// RUN:        --no-offloadlib -fopenmp -fopenmp-targets=spir64 \
+// RUN:        --offload-new-driver %s 2>&1 \
+// RUN:  | FileCheck -check-prefix=CHK-OPENMP-SYCL-PHASES %s
+// CHK-OPENMP-SYCL-PHASES: [[#OMP_DEV:]]: input, "{{.*}}", c++, (device-openmp)
+// CHK-OPENMP-SYCL-PHASES: [[#OMP_DEV+1]]: preprocessor, {[[#OMP_DEV]]}, c++-cpp-output, (device-openmp)
+// CHK-OPENMP-SYCL-PHASES: [[#OMP_DEV+2]]: compiler, {[[#OMP_DEV+1]]}, ir, (device-openmp)
+// CHK-OPENMP-SYCL-PHASES: offload, {{.*}} "device-openmp (spir64)" {[[#OMP_DEV+2]]}, ir
+// CHK-OPENMP-SYCL-PHASES: [[#SYCL_DEV:]]: input, "{{.*}}", c++, (device-sycl)
+// CHK-OPENMP-SYCL-PHASES: [[#SYCL_DEV+1]]: preprocessor, {[[#SYCL_DEV]]}, c++-cpp-output, (device-sycl)
+// CHK-OPENMP-SYCL-PHASES: [[#SYCL_DEV+2]]: compiler, {[[#SYCL_DEV+1]]}, ir, (device-sycl)
+// CHK-OPENMP-SYCL-PHASES: [[#SYCL_DEV+3]]: backend, {[[#SYCL_DEV+2]]}, ir, (device-sycl)
+// CHK-OPENMP-SYCL-PHASES: offload, "device-sycl (spir64-unknown-unknown)" {[[#SYCL_DEV+3]]}, ir