Add trap codes to the Cretonne IL.

The trap and trapz/trapnz instructions now take a trap code immediate
operand which indicates the reason for trapping.

cranelift/filetests/parser/branch.cton

@@ -86,13 +86,13 @@ function %jumptable(i32) {
 
 ebb10(v3: i32):
     br_table v3, jt2
-    trap
+    trap user1
 ebb20:
-    trap
+    trap user2
 ebb30:
-    trap
+    trap user3
 ebb40:
-    trap
+    trap user4
 }
 ; sameln: function %jumptable(i32) native {
 ; nextln:     jt0 = jump_table 0
@@ -100,14 +100,14 @@ ebb40:
 ; nextln: 
 ; nextln: ebb0($v3: i32):
 ; nextln:     br_table $v3, jt1
-; nextln:     trap
+; nextln:     trap user1
 ; nextln: 
 ; nextln: ebb1:
-; nextln:     trap
+; nextln:     trap user2
 ; nextln: 
 ; nextln: ebb2:
-; nextln:     trap
+; nextln:     trap user3
 ; nextln: 
 ; nextln: ebb3:
-; nextln:     trap
+; nextln:     trap user4
 ; nextln: }

cranelift/filetests/parser/instruction_encoding.cton

@@ -7,7 +7,7 @@ isa riscv
 function %foo(i32, i32) {
 ebb1(v0: i32 [%x8], v1: i32):
     [-,-] v2 = iadd v0, v1
-    [-] trap
+    [-] trap heap_oob
     [R#1234, %x5, %x11] v6, v7 = iadd_cout v2, v0
     [Rshamt#beef, %x25] v8 = ishl_imm v6, 2
     v9 = iadd v8, v7
@@ -16,7 +16,7 @@ ebb1(v0: i32 [%x8], v1: i32):
 ; sameln: function %foo(i32, i32) native {
 ; nextln: $ebb1($v0: i32 [%x8], $v1: i32):
 ; nextln:     [-,-]$WS $v2 = iadd $v0, $v1
-; nextln:     [-]$WS trap
+; nextln:     [-]$WS trap heap_oob
 ; nextln:     [R#1234,%x5,%x11]$WS $v6, $v7 = iadd_cout $v2, $v0
 ; nextln:     [Rshamt#beef,%x25]$WS $v8 = ishl_imm $v6, 2
 ; nextln:     [-,-]$WS $v9 = iadd $v8, $v7

cranelift/filetests/parser/rewrite.cton

@@ -13,13 +13,13 @@ function %defs() {
 ebb100(v20: i32):
     v1000 = iconst.i32x8 5
     v9200 = f64const 0x4.0p0
-    trap
+    trap user4
 }
 ; sameln: function %defs() native {
 ; nextln: $ebb100($v20: i32):
 ; nextln:     $v1000 = iconst.i32x8 5
 ; nextln:     $v9200 = f64const 0x1.0000000000000p2
-; nextln:     trap
+; nextln:     trap user4
 ; nextln: }
 
 ; Using values.

cranelift/filetests/parser/tiny.cton

@@ -3,11 +3,11 @@ test cat
 ; The smallest possible function.
 function %minimal() {
 ebb0:
-    trap
+    trap user0
 }
 ; sameln: function %minimal() native {
 ; nextln: ebb0:
-; nextln:     trap
+; nextln:     trap user0
 ; nextln: }
 
 ; Create and use values.