third_party: Adds fuzzer headers via glob

third_party/clang_llvm_12_00_x86_64_linux_gnu_ubuntu_16_04.BUILD

diff --git a/third_party/clang_llvm_12_00_x86_64_linux_gnu_ubuntu_16_04.BUILD b/third_party/clang_llvm_12_00_x86_64_linux_gnu_ubuntu_16_04.BUILD
index 01fffee..9ef72ae 100644
--- a/third_party/clang_llvm_12_00_x86_64_linux_gnu_ubuntu_16_04.BUILD
+++ b/third_party/clang_llvm_12_00_x86_64_linux_gnu_ubuntu_16_04.BUILD
@@ -102,6 +102,7 @@
     hdrs = glob([
         "lib/clang/12.0.0/*.h",
         "lib/clang/12.0.0/include/*.h",
+        "lib/clang/12.0.0/include/**/*.h",
     ]),
     includes = [
         "lib/clang/12.0.0",