Fix php 7.3 build

Author: TysonAndre

tests/setup.sh

@@ -25,6 +25,7 @@ if [[ ! -e "$EXPECTED_AST_FILE" ]]; then
 
   git clone --depth 1 https://github.com/nikic/php-ast.git php-ast
 
+  export CFLAGS="-O3"
   pushd php-ast
   # Install the ast extension
   phpize
@@ -37,10 +38,11 @@ else
   echo "Using cached extension."
 fi
 
-php -r 'function_exists("ast\parse_code") || exit("Failed to enable php-ast");'
-
 echo "extension=$EXPECTED_AST_FILE" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini
 
+php -r 'function_exists("ast\parse_code") || (print("Failed to enable php-ast\n") && exit(1));'
+
 # Disable xdebug, since we aren't currently gathering code coverage data and
 # having xdebug slows down Composer a bit.
-phpenv config-rm xdebug.ini
+# TODO(optional): Once xdebug is enabled for PHP 7.3 on Travis, get rid of the '|| true'
+phpenv config-rm xdebug.ini || true