Remove dependency on glibc 2.27

src/build.sh

@@ -77,6 +77,7 @@ flags="$flags"'
 
   enable_backup_ref_ptr_support=false
   enable_dangling_raw_ptr_checks=false
+  enable_shadow_metadata=false
 '
 
 if [ "$WITH_SYSROOT" ]; then

src/build/linux/sysroot_scripts/reversion_glibc.py

@@ -19,10 +19,6 @@ SECTION_PATTERN = re.compile(r"^ *\[ *[0-9]+\] +(\S+) +\S+ + ([0-9a-f]+) .*$")
 # Some otherwise disallowed symbols are referenced in the linux-chromeos build.
 # To continue supporting it, allow these symbols to remain enabled.
 SYMBOL_ALLOWLIST = {
-    "fts64_close",
-    "fts64_open",
-    "fts64_read",
-    "memfd_create",
 }