Merge pull request #6868 from jckarter/glibc.modulemap.gyb-3.1

Added module ifaddrs

Author: jckarter

stdlib/public/Platform/glibc.modulemap.gyb

@@ -219,6 +219,10 @@ module SwiftGlibc [system] {
       header "${GLIBC_INCLUDE_PATH}/netdb.h"
       export *
     }
+    module ifaddrs {
+      header "${GLIBC_INCLUDE_PATH}/ifaddrs.h"
+      export *
+    }
     module search {
       header "${GLIBC_INCLUDE_PATH}/search.h"
       export *