Add env_include and set CFLAGS for build configuration

Author: mxcl

projects/erlang.org/build.ts

@@ -1,8 +1,10 @@
-import { BuildOptions, unarchive, run } from "brewkit";
+import { env_include, BuildOptions, unarchive, run } from "brewkit";
 
 export default async function ({ prefix, version, deps, tag }: BuildOptions) {
   await unarchive(`https://github.com/erlang/otp/releases/download/${tag}/otp_src_${version}.tar.gz`);
 
+  env_include("gnu.org/gcc");
+
   let extra = Deno.build.os == 'darwin' ? `
     --enable-darwin-64bit
     --enable-kernel-poll
@@ -13,6 +15,8 @@ export default async function ({ prefix, version, deps, tag }: BuildOptions) {
     extra = "LDFLAGS=-Wl,--allow-shlib-undefined";
   }
 
+  Deno.env.set("CFLAGS", "-O3");
+
   run`./configure
         --disable-debug
         --disable-silent-rules