go/packages: add NeedTypesSizes to LoadTypes

This change moves the NeedTypesSizes bit to LoadTypes instead of LoadSyntax.

Fixes golang/go#31163

Change-Id: Icaf16639202533fbb2190756a325b36d8ac9251c
Reviewed-on: https://go-review.googlesource.com/c/tools/+/170016
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>

go/packages/packages.go

@@ -88,14 +88,14 @@ const (
 
 	// LoadTypes adds type information for package-level
 	// declarations in the packages matching the patterns.
-	// Package fields added: Types, Fset, and IllTyped.
+	// Package fields added: Types, TypesSizes, Fset, and IllTyped.
 	// This mode uses type information provided by the build system when
 	// possible, and may fill in the ExportFile field.
-	LoadTypes = LoadImports | NeedTypes
+	LoadTypes = LoadImports | NeedTypes | NeedTypesSizes
 
 	// LoadSyntax adds typed syntax trees for the packages matching the patterns.
 	// Package fields added: Syntax, and TypesInfo, for direct pattern matches only.
-	LoadSyntax = LoadTypes | NeedSyntax | NeedTypesInfo | NeedTypesSizes
+	LoadSyntax = LoadTypes | NeedSyntax | NeedTypesInfo
 
 	// LoadAllSyntax adds typed syntax trees for the packages matching the patterns
 	// and all dependencies.

go/packages/packages_test.go

@@ -569,6 +569,8 @@ func testLoadTypes(t *testing.T, exporter packagestest.Exporter) {
 			continue
 		} else if !p.Types.Complete() {
 			t.Errorf("incomplete types.Package for %s", p)
+		} else if p.TypesSizes == nil {
+			t.Errorf("TypesSizes is not filled in for %s", p)
 		}
 
 	}