gopls/internal/lsp/cache: avoid dependency on StdSizes

Same as CL 516917, but for gopls.

Updates golang/go#61035

Change-Id: Id6cc1d84f7cac06e95a1fb151a7c3f9a8ef25302
Reviewed-on: https://go-review.googlesource.com/c/tools/+/519295
gopls-CI: kokoro <noreply+kokoro@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

gopls/internal/lsp/cache/analysis.go

@@ -707,10 +707,9 @@ func (an *analysisNode) cacheKey() [sha256.Size]byte {
 	// uses those fields, we account for them by hashing vdeps.
 
 	// type sizes
-	// This assertion is safe, but if a black-box implementation
-	// is ever needed, record Sizeof(*int) and Alignof(int64).
-	sz := m.TypesSizes.(*types.StdSizes)
-	fmt.Fprintf(hasher, "sizes: %d %d\n", sz.WordSize, sz.MaxAlign)
+	wordSize := an.m.TypesSizes.Sizeof(types.Typ[types.Int])
+	maxAlign := an.m.TypesSizes.Alignof(types.NewPointer(types.Typ[types.Int64]))
+	fmt.Fprintf(hasher, "sizes: %d %d\n", wordSize, maxAlign)
 
 	// metadata errors: used for 'compiles' field
 	fmt.Fprintf(hasher, "errors: %d", len(m.Errors))

gopls/internal/lsp/cache/check.go

@@ -1401,8 +1401,9 @@ func localPackageKey(inputs typeCheckInputs) source.Hash {
 	}
 
 	// types sizes
-	sz := inputs.sizes.(*types.StdSizes)
-	fmt.Fprintf(hasher, "sizes: %d %d\n", sz.WordSize, sz.MaxAlign)
+	wordSize := inputs.sizes.Sizeof(types.Typ[types.Int])
+	maxAlign := inputs.sizes.Alignof(types.NewPointer(types.Typ[types.Int64]))
+	fmt.Fprintf(hasher, "sizes: %d %d\n", wordSize, maxAlign)
 
 	fmt.Fprintf(hasher, "relatedInformation: %t\n", inputs.relatedInformation)
 	fmt.Fprintf(hasher, "linkTarget: %s\n", inputs.linkTarget)