[clang] [clang] SyntaxWarning: invalid escape sequence '\s' with Python3.12 (PR #78036)

[Jie Fu 傅杰 via cfe-commits]

https://github.com/DamonFool created https://github.com/llvm/llvm-project/pull/78036

The following SyntaxWarning was observed with Python3.12 .
```
llvm-project/clang/tools/libclang/linker-script-to-export-list.py:9: SyntaxWarning: invalid escape sequence '\s'
  m = re.search("^\s+(clang_[^;]+)", line)
```

Similar problem had been reported here https://stackoverflow.com/questions/57645829/why-am-i-getting-a-syntaxwarning-invalid-escape-sequence-s-warning .

It would be better to fix it.
Thanks.


>From 57fa67bf86bea09b9c6011b8c9ec6f69fe11852f Mon Sep 17 00:00:00 2001
From: Jie Fu <jiefu at tencent.com>
Date: Sat, 13 Jan 2024 21:51:36 +0800
Subject: [PATCH] [clang] SyntaxWarning: invalid escape sequence '\s' with
 Python3.12

llvm-project/clang/tools/libclang/linker-script-to-export-list.py:9: SyntaxWarning: invalid escape sequence '\s'
  m = re.search("^\s+(clang_[^;]+)", line)
---
 clang/tools/libclang/linker-script-to-export-list.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/tools/libclang/linker-script-to-export-list.py b/clang/tools/libclang/linker-script-to-export-list.py
index 745996028d835f..35bfa230be704a 100644
--- a/clang/tools/libclang/linker-script-to-export-list.py
+++ b/clang/tools/libclang/linker-script-to-export-list.py
@@ -6,6 +6,6 @@
 output_file = open(sys.argv[2], "w")
 
 for line in input_file:
-    m = re.search("^\s+(clang_[^;]+)", line)
+    m = re.search("^\\s+(clang_[^;]+)", line)
     if m:
         output_file.write(m.group(1) + "\n")