docs: add LLVM exceptions to our Apache 2.0 licensing

LICENSE

@@ -199,3 +199,20 @@
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
+
+
+--- LLVM Exceptions to the Apache 2.0 License ----
+
+As an exception, if, as a result of your compiling your source code, portions
+of this Software are embedded into an Object form of such source code, you
+may redistribute such embedded portions in such Object form without complying
+with the conditions of Sections 4(a), 4(b) and 4(d) of the License.
+
+In addition, if you combine or link compiled forms of this Software with
+software that is licensed under the GPLv2 ("Combined Software") and if a
+court of competent jurisdiction determines that the patent provision (Section
+3), the indemnity provision (Section 9) or other Section of the License
+conflicts with the conditions of the GPLv2, you may retroactively and
+prospectively choose to deem waived or otherwise exclude such Section(s) of
+the License, but only in their entirety and only with respect to the Combined
+Software.

yuujinchou.opam

@@ -6,7 +6,7 @@ This package offers an implementation of nested lexical scoping with an extensib
 """
 maintainer: "favonia <[email protected]>"
 authors: ["The RedPRL Development Team"]
-license: "Apache-2.0"
+license: "Apache-2.0 WITH LLVM-exception"
 homepage: "https://github.com/RedPRL/yuujinchou"
 bug-reports: "https://github.com/RedPRL/yuujinchou/issues"
 dev-repo: "git+https://github.com/RedPRL/yuujinchou.git"