cgo: support full cgo tags

cl/compile.go

@@ -799,10 +799,6 @@ func (p *context) compileInstr(b llssa.Builder, instr ssa.Instruction) {
 	}
 	switch v := instr.(type) {
 	case *ssa.Store:
-		// skip cgo global variables
-		if checkCgo(v.Addr.Name()) {
-			// return
-		}
 		va := v.Addr
 		if va, ok := va.(*ssa.IndexAddr); ok {
 			if args, ok := p.isVArgs(va.X); ok { // varargs: this is a varargs store
@@ -1083,10 +1079,6 @@ func processPkg(ctx *context, ret llssa.Package, pkg *ssa.Package) {
 		case *ssa.Type:
 			ctx.compileType(ret, member)
 		case *ssa.Global:
-			// skip cgo global variables
-			if checkCgo(member.Name()) {
-				// continue
-			}
 			ctx.compileGlobal(ret, member)
 		}
 	}

cl/import.go

@@ -438,13 +438,10 @@ func (p *context) funcName(fn *ssa.Function, ignore bool) (*types.Package, strin
 		if checkCgo(fname) {
 			return nil, fname, llgoInstr
 		}
-		if strings.HasPrefix(fname, "_Cfunc_") {
+		if isCgoCfunc(fn) {
 			if _, ok := llgoInstrs[fname]; ok {
 				return nil, fname, llgoInstr
 			}
-			// fname = fname[7:]
-			// fn.WriteTo(os.Stdout)
-			// return nil, fname, cFunc
 		}
 		if fnPkg := fn.Pkg; fnPkg != nil {
 			pkg = fnPkg.Pkg