diff --git a/benchmarks/string_benchmark.cpp b/benchmarks/string_benchmark.cpp
index aa1e8c9..e6c6570 100644
--- a/benchmarks/string_benchmark.cpp
+++ b/benchmarks/string_benchmark.cpp
@@ -123,3 +123,53 @@
   delete[] s;
 }
 BENCHMARK(BM_string_strlen)->AT_COMMON_SIZES;
+
+static void BM_string_strcat_copy_only(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  std::vector<char> src(nbytes, 'x');
+  std::vector<char> dst(nbytes + 2);
+  src[nbytes - 1] = '\0';
+  dst[0] = 'y';
+  dst[1] = 'y';
+  dst[2] = '\0';
+
+  while (state.KeepRunning()) {
+    strcat(dst.data(), src.data());
+    dst[2] = '\0';
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+BENCHMARK(BM_string_strcat_copy_only)->AT_COMMON_SIZES;
+
+static void BM_string_strcat_seek_only(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  std::vector<char> src(3, 'x');
+  std::vector<char> dst(nbytes + 2, 'y');
+  src[2] = '\0';
+  dst[nbytes - 1] = '\0';
+
+  while (state.KeepRunning()) {
+    strcat(dst.data(), src.data());
+    dst[nbytes - 1] = '\0';
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+BENCHMARK(BM_string_strcat_seek_only)->AT_COMMON_SIZES;
+
+static void BM_string_strcat_half_copy_half_seek(benchmark::State& state) {
+  const size_t nbytes = state.range(0);
+  std::vector<char> src(nbytes / 2, 'x');
+  std::vector<char> dst(nbytes / 2, 'y');
+  src[nbytes / 2 - 1] = '\0';
+  dst[nbytes / 2 - 1] = '\0';
+
+  while (state.KeepRunning()) {
+    strcat(dst.data(), src.data());
+    dst[nbytes / 2 - 1] = '\0';
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
+}
+BENCHMARK(BM_string_strcat_half_copy_half_seek)->AT_COMMON_SIZES;
diff --git a/libc/SECCOMP_WHITELIST.TXT b/libc/SECCOMP_WHITELIST.TXT
index d2ab20e..4cc4f6f 100644
--- a/libc/SECCOMP_WHITELIST.TXT
+++ b/libc/SECCOMP_WHITELIST.TXT
@@ -36,6 +36,9 @@
 int	rt_tgsigqueueinfo:int rt_tgsigqueueinfo(pid_t tgid, pid_t tid, int sig, siginfo_t *uinfo)	all
 int	restart_syscall:int restart_syscall()	all
 int	getrandom:int getrandom(void *buf, size_t buflen, unsigned int flags) all
+int	fstatat64|fstatat:newfstatat(int, const char*, struct stat*, int)	mips64
+int	fstat64|fstat:fstat(int, struct stat*)	mips64
+int	_flush_cache:cacheflush(char* addr, const int nbytes, const int op)	mips64
 
 # Needed for performance tools
 int	perf_event_open:perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu, int group_fd, unsigned long flags)	all
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 5ff3c64..d674630 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -143,7 +143,7 @@
 int ___fchmodat:fchmodat(int, const char*, mode_t)  all
 int fchownat(int, const char*, uid_t, gid_t, int)  all
 int fstatat64|fstatat:fstatat64(int, const char*, struct stat*, int)   arm,mips,x86
-int fstatat64|fstatat:newfstatat(int, const char*, struct stat*, int)  arm64,mips64,x86_64
+int fstatat64|fstatat:newfstatat(int, const char*, struct stat*, int)  arm64,x86_64
 int linkat(int, const char*, int, const char*, int)  all
 int mkdirat(int, const char*, mode_t)  all
 int mknodat(int, const char*, mode_t, dev_t)  all
@@ -187,7 +187,7 @@
 int __statfs:statfs(const char*, struct statfs*)  arm64,mips64,x86_64
 
 int     fstat64|fstat:fstat64(int, struct stat*)    arm,mips,x86
-int     fstat64|fstat:fstat(int, struct stat*)    arm64,mips64,x86_64
+int     fstat64|fstat:fstat(int, struct stat*)    arm64,x86_64
 
 # file system
 int     chdir(const char*)              all
@@ -343,7 +343,7 @@
 int     cacheflush:__ARM_NR_cacheflush(long start, long end, long flags)  arm
 
 # MIPS-specific
-int     _flush_cache:cacheflush(char* addr, const int nbytes, const int op) mips,mips64
+int     _flush_cache:cacheflush(char* addr, const int nbytes, const int op) mips
 int     __set_tls:set_thread_area(void*) mips,mips64
 
 # x86-specific
diff --git a/libc/bionic/wctype.cpp b/libc/bionic/wctype.cpp
index 77f8dde..8e2acef 100644
--- a/libc/bionic/wctype.cpp
+++ b/libc/bionic/wctype.cpp
@@ -36,6 +36,23 @@
 
 #include "private/icu.h"
 
+enum {
+  WC_TYPE_INVALID = 0,
+  WC_TYPE_ALNUM,
+  WC_TYPE_ALPHA,
+  WC_TYPE_BLANK,
+  WC_TYPE_CNTRL,
+  WC_TYPE_DIGIT,
+  WC_TYPE_GRAPH,
+  WC_TYPE_LOWER,
+  WC_TYPE_PRINT,
+  WC_TYPE_PUNCT,
+  WC_TYPE_SPACE,
+  WC_TYPE_UPPER,
+  WC_TYPE_XDIGIT,
+  WC_TYPE_MAX
+};
+
 static bool __icu_hasBinaryProperty(wint_t wc, UProperty property, int (*fallback)(int)) {
   typedef UBool (*FnT)(UChar32, UProperty);
   static auto u_hasBinaryProperty = reinterpret_cast<FnT>(__find_icu_symbol("u_hasBinaryProperty"));
diff --git a/libc/include/wchar.h b/libc/include/wchar.h
index d3e9f5c..c9a78be 100644
--- a/libc/include/wchar.h
+++ b/libc/include/wchar.h
@@ -42,23 +42,6 @@
 
 __BEGIN_DECLS
 
-enum {
-    WC_TYPE_INVALID = 0,
-    WC_TYPE_ALNUM,
-    WC_TYPE_ALPHA,
-    WC_TYPE_BLANK,
-    WC_TYPE_CNTRL,
-    WC_TYPE_DIGIT,
-    WC_TYPE_GRAPH,
-    WC_TYPE_LOWER,
-    WC_TYPE_PRINT,
-    WC_TYPE_PUNCT,
-    WC_TYPE_SPACE,
-    WC_TYPE_UPPER,
-    WC_TYPE_XDIGIT,
-    WC_TYPE_MAX
-};
-
 wint_t            btowc(int);
 int               fwprintf(FILE *, const wchar_t *, ...);
 int               fwscanf(FILE *, const wchar_t *, ...);