Merge changes from topics "revert-2746976-revert-2605644-rulebuilder-ninja-vars-OAAWYCDDLT-KMAGKVIXAT", "sandbox-rust-inputs" into main

* changes:
  support sandboxed rust rules
  conditionally escape rule builder command
  Revert^2 "allow Ninja variables in RuleBuilder API"
  Revert^2 "add crate_root property to rust modules"
  Revert^2 "add rust_toolchain_rustc_prebuilt module type"

cc/testing.go

@@ -35,6 +35,7 @@ func RegisterRequiredBuildComponentsForTest(ctx android.RegistrationContext) {
 
 	multitree.RegisterApiImportsModule(ctx)
 
+	ctx.RegisterModuleType("prebuilt_build_tool", android.NewPrebuiltBuildTool)
 	ctx.RegisterModuleType("cc_benchmark", BenchmarkFactory)
 	ctx.RegisterModuleType("cc_object", ObjectFactory)
 	ctx.RegisterModuleType("cc_genrule", GenRuleFactory)
@@ -67,6 +68,26 @@ func GatherRequiredDepsForTest(oses ...android.OsType) string {
 
 func commonDefaultModules() string {
 	return `
+		prebuilt_build_tool {
+			name: "clang++",
+			src: "bin/clang++",
+		}
+		prebuilt_build_tool {
+			name: "clang++.real",
+			src: "bin/clang++.real",
+		}
+		prebuilt_build_tool {
+			name: "lld",
+			src: "bin/lld",
+		}
+		prebuilt_build_tool {
+			name: "ld.lld",
+			src: "bin/ld.lld",
+		}
+		prebuilt_build_tool {
+			name: "llvm-ar",
+			src: "bin/llvm-ar",
+		}
 		cc_defaults {
 			name: "toolchain_libs_defaults",
 			host_supported: true,
@@ -568,6 +589,12 @@ var PrepareForTestWithCcDefaultModules = android.GroupFixturePreparers(
 
 	// Additional files needed in tests that disallow non-existent source.
 	android.MockFS{
+		"defaults/cc/common/bin/clang++":      nil,
+		"defaults/cc/common/bin/clang++.real": nil,
+		"defaults/cc/common/bin/lld":          nil,
+		"defaults/cc/common/bin/ld.lld":       nil,
+		"defaults/cc/common/bin/llvm-ar":      nil,
+
 		"defaults/cc/common/libc.map.txt":      nil,
 		"defaults/cc/common/libdl.map.txt":     nil,
 		"defaults/cc/common/libm.map.txt":      nil,