[lldb/Reproducers] Serialize empty string for char* methods.

For the methods taking a char* and a length that have a custom replayer,
ignore the incoming string in the instrumentation macro. This prevents
potentially reading garbage and blowing up the SB API log.

lldb/source/API/SBFileSpec.cpp

@@ -143,8 +143,8 @@ void SBFileSpec::SetDirectory(const char *directory) {
 }
 
 uint32_t SBFileSpec::GetPath(char *dst_path, size_t dst_len) const {
-  LLDB_RECORD_DUMMY(uint32_t, SBFileSpec, GetPath, (char *, size_t),
-                           dst_path, dst_len);
+  LLDB_RECORD_METHOD_CONST(uint32_t, SBFileSpec, GetPath, (char *, size_t), "",
+                           dst_len);
 
   uint32_t result = m_opaque_up->GetPath(dst_path, dst_len);