Removed offending flags for Chromium

Removed flags and verified Linux build / execution still works properly.

Change-Id: Ibad4ec5d1b89d8e9b826c57bf2d6dbd0d18b7a2e
Reviewed-on: https://swiftshader-review.googlesource.com/9812
Reviewed-by: Nico Weber <thakis@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index bfd68e2..694942a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -39,7 +39,7 @@
     cflags = [
       "-std=c++11",
       "-Wall",
-      "-fexceptions",
+      "-fno-exceptions",
       "-fno-operator-names",
     ]
 
@@ -59,7 +59,6 @@
         "-ffunction-sections",
         "-fdata-sections",
         "-fomit-frame-pointer",
-        "-O2",
         "-Os",
       ]