[fusl] Remove code for unsupported architectures

fusl/arch/arm/atomic_arch.h

Index: fusl/arch/arm/atomic_arch.h
diff --git a/fusl/arch/arm/atomic_arch.h b/fusl/arch/arm/atomic_arch.h
deleted file mode 100644
index a9a562e4b19a560393387f22be7e8ca0ef745315..0000000000000000000000000000000000000000
--- a/fusl/arch/arm/atomic_arch.h
+++ /dev/null
@@ -1,76 +0,0 @@
-__attribute__((__visibility__(
-    "hidden"))) extern const void* __arm_atomics[3]; /* gettp, cas, barrier */
-
-#if ((__ARM_ARCH_6__ || __ARM_ARCH_6K__ || __ARM_ARCH_6ZK__) && !__thumb__) || \
-    __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
-
-#define a_ll a_ll
-static inline int a_ll(volatile int* p) {
-  int v;
-  __asm__ __volatile__("ldrex %0, %1" : "=r"(v) : "Q"(*p));
-  return v;
-}
-
-#define a_sc a_sc
-static inline int a_sc(volatile int* p, int v) {
-  int r;
-  __asm__ __volatile__("strex %0,%2,%1"
-                       : "=&r"(r), "=Q"(*p)
-                       : "r"(v)
-                       : "memory");
-  return !r;
-}
-
-#if __ARM_ARCH_7A__ || __ARM_ARCH_7R__ || __ARM_ARCH >= 7
-
-#define a_barrier a_barrier
-static inline void a_barrier() {
-  __asm__ __volatile__("dmb ish" : : : "memory");
-}
-
-#endif
-
-#define a_pre_llsc a_barrier
-#define a_post_llsc a_barrier
-
-#else
-
-#define a_cas a_cas
-static inline int a_cas(volatile int* p, int t, int s) {
-  for (;;) {
-    register int r0 __asm__("r0") = t;
-    register int r1 __asm__("r1") = s;
-    register volatile int* r2 __asm__("r2") = p;
-    int old;
-    __asm__ __volatile__("bl __a_cas"
-                         : "+r"(r0)
-                         : "r"(r1), "r"(r2)
-                         : "memory", "r3", "lr", "ip", "cc");
-    if (!r0)
-      return t;
-    if ((old = *p) != t)
-      return old;
-  }
-}
-
-#endif
-
-#ifndef a_barrier
-#define a_barrier a_barrier
-static inline void a_barrier() {
-  __asm__ __volatile__("bl __a_barrier" : : : "memory", "cc", "ip", "lr");
-}
-#endif
-
-#define a_crash a_crash
-static inline void a_crash() {
-  __asm__ __volatile__(
-#ifndef __thumb__
-      ".word 0xe7f000f0"
-#else
-      ".short 0xdeff"
-#endif
-      :
-      :
-      : "memory");
-}