[clang] [llvm] [RISCV] Add sifive-p470 processor (PR #102022)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `flang-x86_64-windows` running on `minipc-ryzen-win` while building `clang,llvm` at step 7 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/166/builds/8

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 7 (test-build-unified-tree-check-flang) failure: test (failure)
******************** TEST 'Flang :: Fir/external-mangling.fir' FAILED ********************
Exit Code: 3221225477

Command Output (stdout):
--
# RUN: at line 1
fir-opt --external-name-interop="append-underscore=true" C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir | c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir --check-prefix=CHECK-UNDER
# executed command: fir-opt --external-name-interop=append-underscore=true 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir'
# executed command: 'c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe' 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir' --check-prefix=CHECK-UNDER
# RUN: at line 2
fir-opt --external-name-interop="append-underscore=false" C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir | c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir --check-prefix=CHECK-NOUNDER
# executed command: fir-opt --external-name-interop=append-underscore=false 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir'
# executed command: 'c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe' 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir' --check-prefix=CHECK-NOUNDER
# RUN: at line 3
tco --external-name-interop="append-underscore=true" C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir | c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir --check-prefix=CHECK-UNDER
# executed command: tco --external-name-interop=append-underscore=true 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir'
# .---command stdout------------
# | module attributes {dlti.dl_spec = #dlti.dl_spec<#dlti.dl_entry<i8, dense<8> : vector<2xi64>>, #dlti.dl_entry<i32, dense<32> : vector<2xi64>>, #dlti.dl_entry<i16, dense<16> : vector<2xi64>>, #dlti.dl_entry<i1, dense<8> : vector<2xi64>>, #dlti.dl_entry<!llvm.ptr, dense<64> : vector<4xi64>>, #dlti.dl_entry<f128, dense<128> : vector<2xi64>>, #dlti.dl_entry<i64, dense<[32, 64]> : vector<2xi64>>, #dlti.dl_entry<f64, dense<64> : vector<2xi64>>, #dlti.dl_entry<f16, dense<16> : vector<2xi64>>, #dlti.dl_entry<"dlti.endianness", "little">>, fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.data_layout = "", llvm.target_triple = "x86_64-pc-windows-msvc"} {
# |   func.func @foo_() attributes {fir.internal_name = "_QPfoo"} {
# |     %c0 = arith.constant 0 : index
# |     %0 = fir.address_of(@a_) : !fir.ref<!fir.array<4xi8>>
# |     %1 = fir.convert %0 : (!fir.ref<!fir.array<4xi8>>) -> !fir.ref<!fir.array<?xi8>>
# |     %2 = fir.coordinate_of %1, %c0 : (!fir.ref<!fir.array<?xi8>>, index) -> !fir.ref<i8>
# |     %3 = fir.convert %2 : (!fir.ref<i8>) -> !fir.ref<i32>
# |     %4 = fir.address_of(@__BLNK__) : !fir.ref<!fir.array<4xi8>>
# |     %5 = fir.convert %4 : (!fir.ref<!fir.array<4xi8>>) -> !fir.ref<!fir.array<?xi8>>
# |     %6 = fir.coordinate_of %5, %c0 : (!fir.ref<!fir.array<?xi8>>, index) -> !fir.ref<i8>
# |     %7 = fir.convert %6 : (!fir.ref<i8>) -> !fir.ref<f32>
# |     fir.call @bar_(%3) : (!fir.ref<i32>) -> ()
# |     fir.call @bar2_(%7) : (!fir.ref<f32>) -> ()
# |     return
# |   }
# |   fir.global common @a_(dense<0> : vector<4xi8>) : !fir.array<4xi8>
# |   fir.global common @__BLNK__(dense<0> : vector<4xi8>) : !fir.array<4xi8>
# |   func.func private @bar_(!fir.ref<i32>) attributes {fir.internal_name = "_QPbar"}
# |   func.func private @bar2_(!fir.ref<f32>) attributes {fir.internal_name = "_QPbar2"}
# |   func.func @callee_() attributes {fir.internal_name = "_QPcallee"} {
# |     fir.call @callee_() : () -> ()
# |     return
# |   }
# |   func.func @caller_() attributes {fir.internal_name = "_QPcaller"} {
# |     fir.call @callee_() : () -> ()
# |     return
# |   }
# | }
# `-----------------------------
# executed command: 'c:\buildbot\flang-x86_64-windows\build\bin\filecheck.exe' 'C:\buildbot\flang-x86_64-windows\llvm-project\flang\test\Fir\external-mangling.fir' --check-prefix=CHECK-UNDER
# note: command had no output on stdout or stderr
# error: command failed with exit status: 0xc0000005

...

```

</details>

https://github.com/llvm/llvm-project/pull/102022