Convert cpp_std to be an attribute instead of a copt.

This attribute is then converted into a feature in cc_library_static.

Fixes: 202518741
Test: CI
Change-Id: I070b56a1e96680ffad0466d085caaab2e9308ebc
diff --git a/cc/library.go b/cc/library.go
index 0cffd56..00e215b 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -248,7 +248,9 @@
 	Linkopts               bazel.StringListAttribute
 	Use_libcrt             bazel.BoolAttribute
 	Rtti                   bazel.BoolAttribute
-	Stl                    *string
+
+	Stl     *string
+	Cpp_std *string
 
 	// This is shared only.
 	Version_script bazel.LabelAttribute
@@ -328,6 +330,7 @@
 		Use_libcrt:                  linkerAttrs.useLibcrt,
 		Rtti:                        compilerAttrs.rtti,
 		Stl:                         compilerAttrs.stl,
+		Cpp_std:                     compilerAttrs.cppStd,
 
 		Version_script: linkerAttrs.versionScript,
 
@@ -2403,6 +2406,7 @@
 			Use_libcrt:             linkerAttrs.useLibcrt,
 			Rtti:                   compilerAttrs.rtti,
 			Stl:                    compilerAttrs.stl,
+			Cpp_std:                compilerAttrs.cppStd,
 			Export_includes:        exportedIncludes.Includes,
 			Export_system_includes: exportedIncludes.SystemIncludes,
 			Local_includes:         compilerAttrs.localIncludes,
@@ -2427,6 +2431,7 @@
 			Use_libcrt: linkerAttrs.useLibcrt,
 			Rtti:       compilerAttrs.rtti,
 			Stl:        compilerAttrs.stl,
+			Cpp_std:    compilerAttrs.cppStd,
 
 			Export_includes:        exportedIncludes.Includes,
 			Export_system_includes: exportedIncludes.SystemIncludes,
@@ -2462,6 +2467,7 @@
 	Use_libcrt bazel.BoolAttribute
 	Rtti       bazel.BoolAttribute
 	Stl        *string
+	Cpp_std    *string
 
 	Export_includes        bazel.StringListAttribute
 	Export_system_includes bazel.StringListAttribute
@@ -2489,6 +2495,7 @@
 	Use_libcrt bazel.BoolAttribute
 	Rtti       bazel.BoolAttribute
 	Stl        *string
+	Cpp_std    *string
 
 	Export_includes        bazel.StringListAttribute
 	Export_system_includes bazel.StringListAttribute