Enable more CLIF tests on AArch64

The tests for the SIMD floating-point maximum and minimum operations
require particular care because the handling of the NaN values is
non-deterministic and may vary between platforms. There is no way to
match several NaN values in a test, so the solution is to extract the
non-deterministic test cases into a separate file that is subsequently
replicated for every backend under test, with adjustments made to the
expected results.

Copyright (c) 2021, Arm Limited.

cranelift/filetests/filetests/licm/br-table.clif

@@ -1,5 +1,6 @@
 test compile
 set opt_level=speed_and_size
+target aarch64
 target x86_64
 
 function %br_table_opt() {
@@ -9,7 +10,7 @@ function %br_table_opt() {
         v0 = iconst.i32 1
         br_table v0, block2, jt0
 
-    block1: 
+    block1:
         return
 
     block2:

cranelift/filetests/filetests/licm/jump-table-entry.clif

@@ -1,4 +1,5 @@
 test licm
+target aarch64
 target x86_64
 
 function %dont_hoist_jump_table_entry_during_licm() {

cranelift/filetests/filetests/licm/load_readonly_notrap.clif

@@ -1,5 +1,6 @@
 test licm
 
+target aarch64
 target x86_64
 
 ;; Nontrapping readonly load from address that is not loop-dependent

cranelift/filetests/filetests/licm/reject_load_notrap.clif

@@ -1,5 +1,6 @@
 test licm
 
+target aarch64
 target x86_64
 
 ;; Nontrapping possibly-not-readonly load from address that is not

cranelift/filetests/filetests/licm/reject_load_readonly.clif

@@ -1,5 +1,6 @@
 test licm
 
+target aarch64
 target x86_64
 
 ;; Maybe-trapping readonly load from address that is not