Use capstone to validate precise-output tests (#5780)

Use the capstone library to disassemble precise-output tests, in addition to pretty-printing their vcode.

cranelift/filetests/filetests/isa/riscv64/atomic_store.clif

@@ -8,9 +8,16 @@ block0(v0: i64, v1: i64):
   return
 }
 
+; VCode:
 ; block0:
 ;   atomic_store.i64 a0,(a1)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   fence rw, w
+;   sd a0, 0(a1)
+;   ret
 
 function %atomic_store_i64_sym(i64) {
   gv0 = symbol colocated %sym
@@ -20,10 +27,22 @@ block0(v0: i64):
   return
 }
 
+; VCode:
 ; block0:
 ;   load_sym t2,%sym+0
 ;   atomic_store.i64 a0,(t2)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   auipc t2, 0
+;   ld t2, 0xc(t2)
+;   j 0xc
+;   .byte 0x00, 0x00, 0x00, 0x00 ; reloc_external Abs8 %sym 0
+;   .byte 0x00, 0x00, 0x00, 0x00
+;   fence rw, w
+;   sd a0, 0(t2)
+;   ret
 
 function %atomic_store_imm_i64(i64) {
 block0(v0: i64):
@@ -32,11 +51,20 @@ block0(v0: i64):
   return
 }
 
+; VCode:
 ; block0:
 ;   lui a1,3
 ;   addi a1,a1,57
 ;   atomic_store.i64 a1,(a0)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   lui a1, 3
+;   addi a1, a1, 0x39
+;   fence rw, w
+;   sd a1, 0(a0)
+;   ret
 
 function %atomic_store_i32(i32, i64) {
 block0(v0: i32, v1: i64):
@@ -44,9 +72,16 @@ block0(v0: i32, v1: i64):
   return
 }
 
+; VCode:
 ; block0:
 ;   atomic_store.i32 a0,(a1)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   fence rw, w
+;   sw a0, 0(a1)
+;   ret
 
 function %atomic_store_i32_sym(i32) {
   gv0 = symbol colocated %sym
@@ -56,10 +91,22 @@ block0(v0: i32):
   return
 }
 
+; VCode:
 ; block0:
 ;   load_sym t2,%sym+0
 ;   atomic_store.i32 a0,(t2)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   auipc t2, 0
+;   ld t2, 0xc(t2)
+;   j 0xc
+;   .byte 0x00, 0x00, 0x00, 0x00 ; reloc_external Abs8 %sym 0
+;   .byte 0x00, 0x00, 0x00, 0x00
+;   fence rw, w
+;   sw a0, 0(t2)
+;   ret
 
 function %atomic_store_imm_i32(i64) {
 block0(v0: i64):
@@ -68,9 +115,18 @@ block0(v0: i64):
   return
 }
 
+; VCode:
 ; block0:
 ;   lui a1,3
 ;   addi a1,a1,57
 ;   atomic_store.i32 a1,(a0)
 ;   ret
+; 
+; Disassembled:
+; block0: ; offset 0x0
+;   lui a1, 3
+;   addi a1, a1, 0x39
+;   fence rw, w
+;   sw a1, 0(a0)
+;   ret