Merge branch 'xamarin-mobile-bindings' into dev/update-m68

diff --cc gn/BUILD.gn
index c206c5529e3c75b5e4c05d508c2b7495be18920a,dcb34815c9b9f23e0625fa354540a5fbd082b041..4d06a697f856a18f4dbaf3f1e8fc38a7d4f9de96
--- 1/gn/BUILD.gn
--- 2/gn/BUILD.gn
+++ b/gn/BUILD.gn
@@@ -519,13 -483,6 +519,13 @@@ config("release") 
      } else {
        ldflags = [ "-s", "-Wl,--gc-sections" ]
      }
-       ldflags += [ "-O3" ]
 +    if (target_cpu == "wasm") {
 +      # The compiler asks us to add an optimization flag to both cflags
 +      # and ldflags to cut down on the local variables,
 +      # for performance reasons.
 +      # The "linking" step is the conversion to javascript.
++      ldflags += [ "-Os" ]
 +    }
    }
    defines = [ "NDEBUG" ]
  }