cmd/go/internal/modload: remove go117EnableLazyLoading

Updates #36460

Change-Id: I19f375f58f118e83a2615a29bbbb3853f059f0bb
Reviewed-on: https://go-review.googlesource.com/c/go/+/345391
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

src/cmd/go/internal/modload/init.go

@@ -709,17 +709,16 @@ func loadModFile(ctx context.Context) (rs *Requirements, needCommit bool) {
 		// cfg.CmdName directly here.
 		if cfg.BuildMod == "mod" && cfg.CmdName != "mod graph" && cfg.CmdName != "mod why" {
 			addGoStmt(MainModules.ModFile(mainModule), mainModule, LatestGoVersion())
-			if go117EnableLazyLoading {
-				// We need to add a 'go' version to the go.mod file, but we must assume
-				// that its existing contents match something between Go 1.11 and 1.16.
-				// Go 1.11 through 1.16 have eager requirements, but the latest Go
-				// version uses lazy requirements instead — so we need to cnvert the
-				// requirements to be lazy.
-				var err error
-				rs, err = convertDepth(ctx, rs, lazy)
-				if err != nil {
-					base.Fatalf("go: %v", err)
-				}
+
+			// We need to add a 'go' version to the go.mod file, but we must assume
+			// that its existing contents match something between Go 1.11 and 1.16.
+			// Go 1.11 through 1.16 have eager requirements, but the latest Go
+			// version uses lazy requirements instead — so we need to convert the
+			// requirements to be lazy.
+			var err error
+			rs, err = convertDepth(ctx, rs, lazy)
+			if err != nil {
+				base.Fatalf("go: %v", err)
 			}
 		} else {
 			rawGoVersion.Store(mainModule, modFileGoVersion(MainModules.ModFile(mainModule)))

src/cmd/go/internal/modload/modfile.go

@@ -45,11 +45,6 @@ const (
 )
 
 const (
-	// go117EnableLazyLoading toggles whether lazy-loading code paths should be
-	// active. It will be removed once the lazy loading implementation is stable
-	// and well-tested.
-	go117EnableLazyLoading = true
-
 	// go1117LazyTODO is a constant that exists only until lazy loading is
 	// implemented. Its use indicates a condition that will need to change if the
 	// main module is lazy.
@@ -103,9 +98,6 @@ const (
 )
 
 func modDepthFromGoVersion(goVersion string) modDepth {
-	if !go117EnableLazyLoading {
-		return eager
-	}
 	if semver.Compare("v"+goVersion, lazyLoadingVersionV) < 0 {
 		return eager
 	}