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

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-darwin` running on `doug-worker-3` while building `clang,llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/23/builds/1711

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: Index/create-libclang-parsing-reproducer.c' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: export LSAN_OPTIONS=detect_leaks=0
+ export LSAN_OPTIONS=detect_leaks=0
+ LSAN_OPTIONS=detect_leaks=0
RUN: at line 2: rm -rf /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp
+ rm -rf /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp
RUN: at line 3: mkdir /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp
+ mkdir /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp
RUN: at line 4: env CINDEXTEST_INVOCATION_EMISSION_PATH=/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp not /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/c-index-test -test-load-source all /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c
+ env CINDEXTEST_INVOCATION_EMISSION_PATH=/Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp not /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/c-index-test -test-load-source all /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c
libclang: crash detected during parsing: {
  'source_filename' : '(null)'
  'command_line_args' : ['clang', '/Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c'],
  'unsaved_files' : [],
  'options' : 1,
}
Unable to load translation unit!
Failure: libclang crashed
RUN: at line 5: /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/clang -cc1gen-reproducer /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp/libclang-* -v | /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/FileCheck /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c
+ /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/clang -cc1gen-reproducer /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/tools/clang/test/Index/Output/create-libclang-parsing-reproducer.c.tmp/libclang-188f6c4dd4b6 -v
+ /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin/FileCheck /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c
clang version 20.0.0git (https://github.com/llvm/llvm-project.git 0c25f85e5b88102363c0cd55e1946053d5827e99)
Target: x86_64-apple-darwin23.6.0
Thread model: posix
InstalledDir: /Volumes/RAMDisk/buildbot-root/x86_64-darwin/build/bin
Build config: +assertions
/Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c:21:16: error: CHECK-NEXT: expected string not found in input
// CHECK-NEXT: "files":["{{.*}}.c","{{.*}}.sh"]
               ^
<stdin>:3:2: note: scanning from here
{
 ^
<stdin>:4:1: note: possible intended match here
"files":[]
^

Input file: <stdin>
Check file: /Volumes/RAMDisk/buildbot-root/x86_64-darwin/llvm-project/clang/test/Index/create-libclang-parsing-reproducer.c

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           1: REPRODUCER METAINFO: {"libclang.operation": "parse", "libclang.opts": "1"} 
           2: REPRODUCER: 
           3: { 
...

```

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