Add remote execution support for clang-tidy actions

Test: Ran with the following command and it succeeded
RBE_CLANG_TIDY="true" RBE_CLANG_TIDY_EXEC_STRATEGY="remote" RBE_CXX_EXEC_STRATEGY="remote_local_fallback" RBE_METALAVA="true" RBE_METALAVA_EXEC_STRATEGY="local" RBE_ABI_LINKER="true" RBE_ABI_LINKER_EXEC_STRATEGY="remote_local_fallback" RBE_CXX_LINKS="true" RBE_CXX_LINKS_EXEC_STRATEGY="remote" use_rbe m out/soong/.intermediates/external/android-clat/clatd/android_arm_armv7-a-neon/obj/external/android-clat/icmp.tidy

Bug: b/157147559
Change-Id: I110b6157fc090abd14ac32330fc59a3d76cdfa82

cc/builder.go

@@ -174,12 +174,21 @@ var (
 		},
 		"crossCompile", "format")
 
-	clangTidy = pctx.AndroidStaticRule("clangTidy",
+	clangTidy, clangTidyRE = remoteexec.StaticRules(pctx, "clangTidy",
 		blueprint.RuleParams{
-			Command:     "rm -f $out && ${config.ClangBin}/clang-tidy $tidyFlags $in -- $cFlags && touch $out",
+			Command:     "rm -f $out && $reTemplate${config.ClangBin}/clang-tidy $tidyFlags $in -- $cFlags && touch $out",
 			CommandDeps: []string{"${config.ClangBin}/clang-tidy"},
 		},
-		"cFlags", "tidyFlags")
+		&remoteexec.REParams{
+			Labels:       map[string]string{"type": "lint", "tool": "clang-tidy", "lang": "cpp"},
+			ExecStrategy: "${config.REClangTidyExecStrategy}",
+			Inputs:       []string{"$in"},
+			// OutputFile here is $in for remote-execution since its possible that
+			// clang-tidy modifies the given input file itself and $out refers to the
+			// ".tidy" file generated for ninja-dependency reasons.
+			OutputFiles:  []string{"$in"},
+			Platform:     map[string]string{remoteexec.PoolKey: "${config.REClangTidyPool}"},
+		}, []string{"cFlags", "tidyFlags"}, []string{})
 
 	_ = pctx.SourcePathVariable("yasmCmd", "prebuilts/misc/${config.HostPrebuiltTag}/yasm/yasm")
 
@@ -569,8 +578,13 @@ func TransformSourceToObj(ctx android.ModuleContext, subdir string, srcFiles and
 			tidyFile := android.ObjPathWithExt(ctx, subdir, srcFile, "tidy")
 			tidyFiles = append(tidyFiles, tidyFile)
 
+			rule := clangTidy
+			if ctx.Config().IsEnvTrue("RBE_CLANG_TIDY") {
+				rule = clangTidyRE
+			}
+
 			ctx.Build(pctx, android.BuildParams{
-				Rule:        clangTidy,
+				Rule:        rule,
 				Description: "clang-tidy " + srcFile.Rel(),
 				Output:      tidyFile,
 				Input:       srcFile,