[llvm][utils] Improve the StringRef summary provider (#162298)

- check the length of data before casting as `char[N]` because the will
cause lldb to allocate `N` bytes of memory.

---------

Co-authored-by: Dave Lee <davelee.com@gmail.com>

llvm/utils/lldbDataFormatters.py

diff --git a/llvm/utils/lldbDataFormatters.py b/llvm/utils/lldbDataFormatters.py
index 5e553ca..a3e4ae1 100644
--- a/llvm/utils/lldbDataFormatters.py
+++ b/llvm/utils/lldbDataFormatters.py
@@ -197,6 +197,11 @@
         return '""'
 
     data = data_pointer.deref
+    # StringRef may be uninitialized with length exceeding available memory,
+    # potentially causing bad_alloc exceptions. Limit the length to max string summary setting.
+    limit_obj = valobj.target.debugger.GetSetting("target.max-string-summary-length")
+    if limit_obj:
+        length = min(length, limit_obj.GetUnsignedIntegerValue())
     # Get a char[N] type, from the underlying char type.
     array_type = data.type.GetArrayType(length)
     # Cast the char* string data to a char[N] array.