go-fuzz-build: use _go_fuzz_dep_.Bool instead of bool in generated code

This avoids compilation errors when user code shadows the built-in bool,
as happens (for example) in cmd/compile.

go-fuzz-build/cover.go

@@ -224,7 +224,8 @@ func (s *Sonar) Visit(n ast.Node) ast.Visitor {
 	// Replace:
 	//	x != y
 	// with:
-	//	func() bool { v1 := x; v2 := y; go-fuzz-dep.Sonar(v1, v2, flags); return v1 != v2 }() == true
+	//	func() _go_fuzz_dep_.Bool { v1 := x; v2 := y; go-fuzz-dep.Sonar(v1, v2, flags); return v1 != v2 }() == true
+	// Using "== true" lets us modify the AST Node in-place.
 	v1 := nn.X
 	v2 := nn.Y
 	ast.Walk(s, v1)
@@ -339,7 +340,7 @@ func (s *Sonar) Visit(n ast.Node) ast.Visitor {
 	)
 	nn.X = &ast.CallExpr{
 		Fun: &ast.FuncLit{
-			Type: &ast.FuncType{Results: &ast.FieldList{List: []*ast.Field{{Type: ast.NewIdent("bool")}}}},
+			Type: &ast.FuncType{Results: &ast.FieldList{List: []*ast.Field{{Type: ast.NewIdent("_go_fuzz_dep_.Bool")}}}},
 			Body: block,
 		},
 	}

go-fuzz-dep/main.go

@@ -15,6 +15,11 @@ import (
 	. "go-fuzz-defs"
 )
 
+// Bool is just a bool.
+// It is used by code autogenerated by go-fuzz-build
+// to avoid compilation errors when a user's code shadows the built-in bool.
+type Bool bool
+
 var (
 	inFD  FD
 	outFD FD

test/test.go

@@ -185,3 +185,12 @@ func test6() {
 func issue194(v testdep.I) testdep.I {
 	return testdep.B(v == testdep.V1{} || v == testdep.V2{})
 }
+
+func shadowedBool() {
+	var bool int
+	var x int
+	if x == 0 {
+		return
+	}
+	_ = bool
+}