Bump the platform default up to C17.

This is already the "default default" for gcc and clang.

Bug: http://b/232413369
Test: treehugger
Change-Id: I3c0df7c63e8fca1b7692ad867d349a645559c209
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 701c3bb..859059e 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -4981,7 +4981,7 @@
 	cppOnly := []string{"-fPIC", "${config.CommonGlobalCppflags}", "${config.DeviceGlobalCppflags}", "${config.ArmCppflags}"}
 
 	cflags := []string{"-Werror", "-std=candcpp"}
-	cstd := []string{"-std=gnu11", "-std=conly"}
+	cstd := []string{"-std=gnu17", "-std=conly"}
 	cppstd := []string{"-std=gnu++17", "-std=cpp", "-fno-rtti"}
 
 	lastIncludes := []string{
diff --git a/cc/config/global.go b/cc/config/global.go
index d63e324..8ff5f55 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -298,9 +298,9 @@
 		"-w",
 	}
 
-	CStdVersion               = "gnu11"
+	CStdVersion               = "gnu17"
 	CppStdVersion             = "gnu++17"
-	ExperimentalCStdVersion   = "gnu17"
+	ExperimentalCStdVersion   = "gnu2x"
 	ExperimentalCppStdVersion = "gnu++2a"
 
 	// prebuilts/clang default settings.