Expressions display incorrectly in watch window

Environemnt:

• VSCode Version: 1.11.2
• Cpptools: \cpvsbuild\Drops\MDDDebugger\CppTools\20170425.3\Extension\cpptools.vsix
• OS Version: Win10 x64

Steps to Reproduce:

1. Open attachment in vscode.
2. Set breakpoints at the line of 87,89 in source.cpp and 9,12 in mylib.cpp.
3. Press F5 to start debugging(hit 87 line in source.cpp file).
4. Press F5(hit 9 line in mylib.cpp file)->F10(hit 10 line in mylib.cpp file)->F5(hit 12 line in mylib.cpp file)->F5(hit 89 line in mylib.cpp file).
5. Evaluate function "myclass->DisplayAge(30)" in watch window ,It inputs "Cannot evaluate function -- may be inlined"
   
6. Evaluate myclass->DisplayAge(30)" again.

Excepted:
It inputs "Cannot evaluate function -- may be inlined"

Actual:
It value is "-var-create: unable to create variable object"

Log:log.txt

首先使用 source.cpp、mylib.cpp、链接的附件和 log.txt 重现 watch 窗口序列。比较对 myclass->DisplayAge(30) 的第一次和第二次求值，并检查调试器输出以了解不同的结果。完成的标准是重复求值始终报告预期消息，而不是 -var-create: unable to create variable object。