[NVPTX] generated debug info uses features not available in older PTX versions

[Artem-B]

Reproducer:

LLVM_PTXAS_EXECUTABLE=$HOME/local/cuda-11.8.0/bin/ptxas bin/llvm-lit -av $HOME/work/llvm/repo/llvm/test/DebugInfo/NVPTX/dbg-value-const-byref.ll
+ bin/llc -mtriple=nvptx64-nvidia-cuda
+ local/cuda-11.8.0/bin/ptxas -arch=sm_60 -c -
ptxas /tmp/lit-tmp-3piyjb1a/tmpxft_00096c16_00000000-0_stdin, line 91; error   : Feature 'Defining labels in .section' requires PTX ISA .version 7.0 or later
ptxas fatal   : Ptx assembly aborted due to errors

The label ptxas is unhappy about:

     88         .file   1 "dbg-value-const-byref.c"
     89         .section        .debug_loc
     90         {
     91 $L__debug_loc0:
     92 .b64 $L__tmp0
     93 .b64 $L__tmp1

[llvmbot]

@llvm/issue-subscribers-debuginfo

Author: Artem Belevich (Artem-B)

Reproducer: ``` LLVM_PTXAS_EXECUTABLE=$HOME/local/cuda-11.8.0/bin/ptxas bin/llvm-lit -av $HOME/work/llvm/repo/llvm/test/DebugInfo/NVPTX/dbg-value-const-byref.ll + bin/llc -mtriple=nvptx64-nvidia-cuda + local/cuda-11.8.0/bin/ptxas -arch=sm_60 -c - ptxas /tmp/lit-tmp-3piyjb1a/tmpxft_00096c16_00000000-0_stdin, line 91; error : Feature 'Defining labels in .section' requires PTX ISA .version 7.0 or later ptxas fatal : Ptx assembly aborted due to errors

The label ptxas is unhappy about:

 88         .file   1 "dbg-value-const-byref.c"
 89         .section        .debug_loc
 90         {
 91 $L__debug_loc0:
 92 .b64 $L__tmp0
 93 .b64 $L__tmp1

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