[clang][utils] Remove StringRef lldb summary provider

[kastiglione]

Summary

Remove the StringRef summary provider in favor of the implementation in
llvm/utils/lldbDataFormatters.py.

This implementation was resulting in errors in some cases.

[kastiglione]

The StringRef provider was improved in D117779.

clang/utils/ClangDataFormat.py

 (clang::SourceLocation) $4 = "/usr/include/i386/_types.h:37:1" (offset: 123582, file, local)
 """
 
 import lldb
 
 def __lldb_init_module(debugger, internal_dict):
   debugger.HandleCommand("type summary add -F ClangDataFormat.SourceLocation_summary clang::SourceLocation")
   debugger.HandleCommand("type summary add -F ClangDataFormat.QualType_summary clang::QualType")
-  debugger.HandleCommand("type summary add -F ClangDataFormat.StringRef_summary llvm::StringRef")
 
 def SourceLocation_summary(srcloc, internal_dict):
   return SourceLocation(srcloc).summary()
 
 def QualType_summary(qualty, internal_dict):
   return QualType(qualty).summary()
 
-def StringRef_summary(strref, internal_dict):
-  return StringRef(strref).summary()
-
 class SourceLocation(object):
   def __init__(self, srcloc):
     self.srcloc = srcloc
     self.ID = srcloc.GetChildAtIndex(0).GetValueAsUnsigned()
     self.frame = srcloc.GetFrame()
   
   def offset(self):
     return getValueFromExpression(self.srcloc, ".getOffset()").GetValueAsUnsigned()
def getAsString(self):
     return std_str.GetSummary()
 
   def summary(self):
     desc = self.getAsString()
     if desc == '"NULL TYPE"':
       return "<NULL TYPE>"
     return desc
 
-class StringRef(object):
-  def __init__(self, strref):
-    self.strref = strref
-    self.Data_value = strref.GetChildAtIndex(0)
-    self.Length = strref.GetChildAtIndex(1).GetValueAsUnsigned()
-
-  def summary(self):
-    if self.Length == 0:
-      return '""'
-    data = self.Data_value.GetPointeeData(0, self.Length)
-    error = lldb.SBError()
-    string = data.ReadRawData(error, 0, data.GetByteSize())
-    if error.Fail():
-      return None
-    return '"%s"' % string
-
-
 # Key is a (function address, type name) tuple, value is the expression path for
 # an object with such a type name from inside that function.
 FramePathMapCache = {}
 
 def findObjectExpressionPath(typename, frame):
   func_addr = frame.GetFunction().GetStartAddress().GetFileAddress()
   key = (func_addr, typename)
   try: