Add gl_BaseInstance to the name mapper. (#3462)

diff --git a/source/name_mapper.cpp b/source/name_mapper.cpp
index 43fdfb3..5525bbc 100644
--- a/source/name_mapper.cpp
+++ b/source/name_mapper.cpp
@@ -153,6 +153,7 @@
     CASE(SubgroupLocalInvocationId)
     GLCASE(VertexIndex)
     GLCASE(InstanceIndex)
+    GLCASE(BaseInstance)
     CASE(SubgroupEqMaskKHR)
     CASE(SubgroupGeMaskKHR)
     CASE(SubgroupGtMaskKHR)
diff --git a/test/name_mapper_test.cpp b/test/name_mapper_test.cpp
index 00fbeed..759c705 100644
--- a/test/name_mapper_test.cpp
+++ b/test/name_mapper_test.cpp
@@ -270,6 +270,7 @@
         BuiltInCase("SubgroupLocalInvocationId"),
         BuiltInGLCase("VertexIndex"),
         BuiltInGLCase("InstanceIndex"),
+        BuiltInGLCase("BaseInstance"),
         BuiltInCase("SubgroupEqMaskKHR"),
         BuiltInCase("SubgroupGeMaskKHR"),
         BuiltInCase("SubgroupGtMaskKHR"),