sagemathgh-38034: sage.libs.giac: Compile with std=c++11

    
<!-- ^ Please provide a concise and informative title. -->
<!-- ^ Don't put issue numbers in the title, do this in the PR
description below. -->
<!-- ^ For example, instead of "Fixes sagemath#12345" use "Introduce new method
to calculate 1 + 2". -->
<!-- v Describe your changes below in detail. -->
<!-- v Why is this change required? What problem does it solve? -->
<!-- v If this PR resolves an open issue, please link to it here. For
example, "Fixes sagemath#12345". -->

Fixes
sagemath#37998 (comment)

- Split out from sagemath#37998

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->

- [x] The title is concise and informative.
- [ ] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation and checked the documentation
preview.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on. For example,
-->
<!-- - sagemath#12345: short description why this is a dependency -->
<!-- - sagemath#34567: ... -->
    
URL: sagemath#38034
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee

src/sage/libs/giac/giac.pyx

@@ -1,5 +1,6 @@
 # distutils: libraries = giac
 # distutils: language = c++
+# distutils: extra_compile_args = -std=c++11
 r"""
 Interface to the c++ giac library.