Only enable shared libc++ for ASan, MSan and TSan builds.

third_party/libc++/BUILD.gn

Index: third_party/libc++/BUILD.gn
diff --git a/third_party/libc++/BUILD.gn b/third_party/libc++/BUILD.gn
index a236b80ddcb879bf66dfbf92b9354c6a2d563f13..1297799b583cb86ff12ef9b20c3a61fb456f5d05 100644
--- a/third_party/libc++/BUILD.gn
+++ b/third_party/libc++/BUILD.gn
@@ -5,10 +5,10 @@
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/toolchain.gni")
 
-# Sanitizer builds need to override operator new, operator delete, and
+# ASan, MSan and TSan need to override operator new, operator delete, and
 # some exception handling symbols, so libc++ must be a shared library
 # to prevent duplicate symbol errors when linking.
-libcpp_is_static = !is_component_build && !using_sanitizer
+libcpp_is_static = !is_component_build && !is_asan && !is_msan && !is_tsan
 
 # Used by libc++ and libc++abi.
 config("config") {