Code style/whitespace cleanup; remove obsolete headers.

And move the MAP_ANON redefinition from py/asmx64.c to unix/alloc.c.
diff --git a/py/asmarm.c b/py/asmarm.c
index fff95fd..da9f409 100644
--- a/py/asmarm.c
+++ b/py/asmarm.c
@@ -84,16 +84,15 @@
         if(as->code_base == NULL) {
             assert(0);
         }
-    }
-    else if(as->pass == ASM_ARM_PASS_EMIT) {
+    } else if(as->pass == ASM_ARM_PASS_EMIT) {
 #ifdef __arm__
         // flush I- and D-cache
-	asm volatile(
+        asm volatile(
                 "0:"
                 "mrc p15, 0, r15, c7, c10, 3\n"
                 "bne 0b\n"
                 "mov r0, #0\n"
-	        "mcr p15, 0, r0, c7, c7, 0\n"
+                "mcr p15, 0, r0, c7, c7, 0\n"
                 : : : "r0", "cc");
 #endif
     }
diff --git a/py/asmx64.c b/py/asmx64.c
index cf9d8b0..940bd9e 100644
--- a/py/asmx64.c
+++ b/py/asmx64.c
@@ -35,15 +35,8 @@
 // wrapper around everything in this file
 #if MICROPY_EMIT_X64
 
-#include <sys/types.h>
-#include <sys/mman.h>
-
 #include "asmx64.h"
 
-#if defined(__OpenBSD__) || defined(__MACH__)
-#define MAP_ANONYMOUS MAP_ANON
-#endif
-
 /* all offsets are measured in multiples of 8 bytes */
 #define WORD_SIZE                (8)
 
@@ -164,7 +157,7 @@
 void asm_x64_end_pass(asm_x64_t *as) {
     if (as->pass == ASM_X64_PASS_COMPUTE) {
         MP_PLAT_ALLOC_EXEC(as->code_offset, (void**) &as->code_base, &as->code_size);
-	if(as->code_base == NULL) {
+        if(as->code_base == NULL) {
             assert(0);
         }
         //printf("code_size: %u\n", as->code_size);
diff --git a/py/compile.c b/py/compile.c
index 267eb2c..d920187 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -3692,7 +3692,7 @@
 #elif MICROPY_EMIT_THUMB
         emit_native_thumb_free(emit_native);
 #elif MICROPY_EMIT_ARM
-	emit_native_arm_free(emit_native);
+        emit_native_arm_free(emit_native);
 #endif
     }
 #endif
diff --git a/py/emitnative.c b/py/emitnative.c
index 6e064fc..1e1596c 100644
--- a/py/emitnative.c
+++ b/py/emitnative.c
@@ -394,7 +394,7 @@
         void *f = asm_thumb_get_code(emit->as);
         mp_uint_t f_len = asm_thumb_get_code_size(emit->as);
 #elif N_ARM
-	void *f = asm_arm_get_code(emit->as);
+        void *f = asm_arm_get_code(emit->as);
         mp_uint_t f_len = asm_arm_get_code_size(emit->as);
 #endif