bp2build allowlist //external/libcxx/...

Test: b build //external/libcxx/...
Fixes: 197954422
Change-Id: If5285f161a9e15f3401b442d699464f522124d3d
diff --git a/android/bazel.go b/android/bazel.go
index bebb61b..e392aa5 100644
--- a/android/bazel.go
+++ b/android/bazel.go
@@ -141,6 +141,7 @@
 		"build/bazel/bazel_skylib":/* recursive = */ true,
 		"build/bazel/rules":/* recursive = */ true,
 		"build/bazel/rules_cc":/* recursive = */ true,
+		"build/bazel/scripts":/* recursive = */ true,
 		"build/bazel/tests":/* recursive = */ true,
 		"build/bazel/platforms":/* recursive = */ true,
 		"build/bazel/product_variables":/* recursive = */ true,
@@ -173,6 +174,7 @@
 		"external/arm-optimized-routines": Bp2BuildDefaultTrueRecursively,
 		"external/fmtlib":                 Bp2BuildDefaultTrueRecursively,
 		"external/jemalloc_new":           Bp2BuildDefaultTrueRecursively,
+		"external/libcxx":                 Bp2BuildDefaultTrueRecursively,
 		"external/libcxxabi":              Bp2BuildDefaultTrueRecursively,
 		"external/scudo":                  Bp2BuildDefaultTrueRecursively,
 		"prebuilts/clang/host/linux-x86":  Bp2BuildDefaultTrueRecursively,
@@ -237,6 +239,7 @@
 	// Per-module denylist to opt modules out of mixed builds. Such modules will
 	// still be generated via bp2build.
 	mixedBuildsDisabledList = []string{
+		"libc++_static",  // "error: no member named 'signbit' in the global namespace; did you mean 'sigwait'?"
 		"libc++abi",      // http://b/195970501, cc_library_static, duplicate symbols because it propagates libc objects.
 		"libc++demangle", // http://b/195970501, cc_library_static, duplicate symbols because it propagates libc objects.
 	}