[Clang] Increase default architecture from sm_35 to sm_52

We previously defaulted to `sm_35` for the purpose of unspecified
architecture. This was removed in new CUDA versions so we should bump
this up.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D156936

Author: jhuber6

clang/include/clang/Basic/Cuda.h

@@ -117,7 +117,7 @@ enum class CudaArch {
            // public one.
   LAST,
 
-  CudaDefault = CudaArch::SM_35,
+  CudaDefault = CudaArch::SM_52,
   HIPDefault = CudaArch::GFX803,
 };
 

clang/test/Driver/cuda-cross-compiling.c

@@ -65,9 +65,9 @@
 // RUN: %clang --target=nvptx64-nvidia-cuda -### --cuda-path=%S/Inputs/CUDA/usr/local/cuda %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=DEFAULT %s
 
-//      DEFAULT: -cc1" "-triple" "nvptx64-nvidia-cuda" "-S" {{.*}} "-target-cpu" "sm_35" "-target-feature" "+ptx{{[0-9]+}}" {{.*}} "-o" "[[PTX:.+]].s"
-// DEFAULT-NEXT: ptxas{{.*}}"-m64" "-O0" "--gpu-name" "sm_35" "--output-file" "[[CUBIN:.+]].cubin" "[[PTX]].s" "-c"
-// DEFAULT-NEXT: nvlink{{.*}}"-o" "a.out" "-arch" "sm_35" {{.*}} "[[CUBIN]].cubin"
+//      DEFAULT: -cc1" "-triple" "nvptx64-nvidia-cuda" "-S" {{.*}} "-target-cpu" "sm_52" "-target-feature" "+ptx{{[0-9]+}}" {{.*}} "-o" "[[PTX:.+]].s"
+// DEFAULT-NEXT: ptxas{{.*}}"-m64" "-O0" "--gpu-name" "sm_52" "--output-file" "[[CUBIN:.+]].cubin" "[[PTX]].s" "-c"
+// DEFAULT-NEXT: nvlink{{.*}}"-o" "a.out" "-arch" "sm_52" {{.*}} "[[CUBIN]].cubin"
 
 //
 // Test to ensure that we enable handling global constructors in a freestanding