[clang][Driver] Add ROCm lib/llvm/bin detection test

clang/test/Driver/rocm-detect-lib-llvm.hip

@@ -0,0 +1,28 @@
+// UNSUPPORTED: system-windows
+//
+// Copying clang to a new location and running it will not work unless it is
+// statically linked. Dynamically linked builds typically use relative rpaths,
+// which this will break.
+// REQUIRES: static-libs
+//
+// Test detecting ROCm installation from clang installed in /opt/rocm/lib/llvm/bin.
+// This exercises the RocmInstallationDetector logic that backs up from
+// /opt/rocm/lib/llvm/bin to the ROCm root, while avoiding dependence on any
+// real /opt/rocm installation by using a synthetic sysroot under %t.
+//
+// RUN: rm -rf %t/*
+// Set up a fake ROCm installation rooted at /opt/rocm in the synthetic sysroot
+// so that the device libraries and HIP runtime can be found.
+// RUN: mkdir -p %t/sysroot/opt/rocm
+// RUN: cp -r %S/Inputs/rocm/* %t/sysroot/opt/rocm
+// Copy the built clang binary so that its InstalledDir and the real path used
+// by the driver both reside under /opt/rocm/lib/llvm/bin, which is what the
+// detection logic inspects.
+// RUN: mkdir -p %t/sysroot/opt/rocm/lib/llvm/bin
+// RUN: cp %clang %t/sysroot/opt/rocm/lib/llvm/bin/clang
+// RUN: %t/sysroot/opt/rocm/lib/llvm/bin/clang -### --target=x86_64-linux-gnu \
+// RUN:   --offload-arch=gfx1010 --print-rocm-search-dirs %s 2>&1 \
+// RUN:   | FileCheck -check-prefixes=ROCM-LIB-LLVM %s
+//
+// ROCM-LIB-LLVM: ROCm installation search path: {{.*sysroot/opt/rocm$}}
+// ROCM-LIB-LLVM-NOT: ROCm installation search path: {{.*sysroot/opt/rocm/lib$}}