No longer needed to set EXTRA_CFLAGS for prism

Author: eregon

mx.truffleruby/suite.py

@@ -224,11 +224,6 @@
             "dir": "src/main/c/yarp",
             # "makeTarget": "all-no-debug", # Can use this to build without asserts
             "results": ["build/librubyparser.a"],
-            "buildEnv": {
-                # system clang on macOS Mojave warns+errors for `mystruct s = { 0 };` when there are struct fields.
-                # newer compiler do not warn for this.
-                "EXTRA_CFLAGS": "-Wno-missing-braces",
-            },
             "description": "YARP used as a static library"
         },