[fusl] Remove code for unsupported architectures

fusl/arch/powerpc/pthread_arch.h

Index: fusl/arch/powerpc/pthread_arch.h
diff --git a/fusl/arch/powerpc/pthread_arch.h b/fusl/arch/powerpc/pthread_arch.h
deleted file mode 100644
index 10b0a2c55c013d2e4b612b10de08f19ac7bd7a1f..0000000000000000000000000000000000000000
--- a/fusl/arch/powerpc/pthread_arch.h
+++ /dev/null
@@ -1,21 +0,0 @@
-static inline struct pthread* __pthread_self() {
-#ifdef __clang__
-  char* tp;
-  __asm__ __volatile__("mr %0, 2" : "=r"(tp) : :);
-#else
-  register char* tp __asm__("r2");
-  __asm__ __volatile__("" : "=r"(tp));
-#endif
-  return (pthread_t)(tp - 0x7000 - sizeof(struct pthread));
-}
-
-#define TLS_ABOVE_TP
-#define TP_ADJ(p) ((char*)(p) + sizeof(struct pthread) + 0x7000)
-
-#define DTP_OFFSET 0x8000
-
-// the kernel calls the ip "nip", it's the first saved value after the 32
-// GPRs.
-#define MC_PC gregs[32]
-
-#define CANARY canary_at_end