Add Regal bundle compilation benchmark (#1618)

This is really testing OPA rather than Regal, but since it's
a good test case for improving OPA for Regal, it belongs here.

Used in open-policy-agent/opa#7740

Signed-off-by: Anders Eknert <anders@styra.com>

Author: anderseknert

.golangci.yaml

@@ -80,6 +80,7 @@ linters:
       - path: '(.+)_test\.go'
         linters:
           - forcetypeassert
+          - godot
     generated: lax
     presets:
       - comments

internal/compile/compile_bench_test.go

@@ -0,0 +1,21 @@
+package compile
+
+import (
+	"testing"
+
+	"github.com/styrainc/regal/bundle"
+)
+
+// 16	  66555594 ns/op	50239492 B/op	 1083664 allocs/op - main
+// 18	  62569440 ns/op	38723015 B/op	  944277 allocs/op - compiler-optimizations pr
+func BenchmarkCompileBundle(b *testing.B) {
+	bndl := bundle.LoadedBundle
+
+	compiler := NewCompilerWithRegalBuiltins()
+
+	for b.Loop() {
+		if compiler.Compile(bndl.ParsedModules("regal")); len(compiler.Errors) > 0 {
+			b.Fatal(compiler.Errors)
+		}
+	}
+}