cmd/compile/internal/ssa: remove Func.StaticData field

Rather than collecting static data nodes to be written out later, just
write them out immediately.

Change-Id: I51708b690e94bc3e288b4d6ba3307bf738a80f64
Reviewed-on: https://go-review.googlesource.com/36352
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

src/cmd/compile/internal/gc/ssa.go

@@ -642,15 +642,11 @@ func (s *state) stmt(n *Node) {
 		b.AddEdgeTo(lab.target)
 
 	case OAS, OASWB:
-		// Check whether we can generate static data rather than code.
-		// If so, ignore n and defer data generation until codegen.
-		// Failure to do this causes writes to readonly symbols.
+		// Generate static data rather than code, if possible.
 		if gen_as_init(n, true) {
-			var data []*Node
-			if s.f.StaticData != nil {
-				data = s.f.StaticData.([]*Node)
+			if !gen_as_init(n, false) {
+				Fatalf("non-static data marked as static: %v\n\n", n)
 			}
-			s.f.StaticData = append(data, n)
 			return
 		}
 
@@ -4487,15 +4483,6 @@ func genssa(f *ssa.Func, ptxt *obj.Prog, gcargs, gclocals *Sym) {
 		}
 	}
 
-	// Emit static data
-	if f.StaticData != nil {
-		for _, n := range f.StaticData.([]*Node) {
-			if !gen_as_init(n, false) {
-				Fatalf("non-static data marked as static: %v\n\n", n)
-			}
-		}
-	}
-
 	// Generate gc bitmaps.
 	liveness(Curfn, ptxt, gcargs, gclocals)
 

src/cmd/compile/internal/ssa/func.go

@@ -18,7 +18,6 @@ type Func struct {
 	pass   *pass    // current pass information (name, options, etc.)
 	Name   string   // e.g. bytes·Compare
 	Type   Type     // type signature of the function.
-	StaticData interface{} // associated static data, untouched by the ssa package
 	Blocks []*Block // unordered set of all basic blocks (note: not indexable by ID)
 	Entry  *Block   // the entry basic block
 	bid    idAlloc  // block ID allocator