[AArch64][GlobalISel] Mark G_TRAP, G_DEBUGTRAP and G_UBSANTRAP as legal. NFC

Similar to #153545 these nodes are always legal for AArch64, this patch marks
them so to reduce the dependency on the legacy legalizer ruleset.

Author: davemgreen

llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp

@@ -1259,6 +1259,8 @@ AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST)
 
   getActionDefinitionsBuilder(G_BRJT).legalFor({{p0, s64}});
 
+  getActionDefinitionsBuilder({G_TRAP, G_DEBUGTRAP, G_UBSANTRAP}).alwaysLegal();
+
   getActionDefinitionsBuilder(G_DYN_STACKALLOC).custom();
 
   getActionDefinitionsBuilder({G_STACKSAVE, G_STACKRESTORE}).lower();

llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir

@@ -857,14 +857,16 @@
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_TRAP (opcode {{[0-9]+}}): 0 type indices, 0 imm indices
-# DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
-# DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_DEBUGTRAP (opcode {{[0-9]+}}): 0 type indices, 0 imm indices
-# DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
-# DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_UBSANTRAP (opcode {{[0-9]+}}): 0 type indices, 0 imm indices
-# DEBUG-NEXT: .. type index coverage check SKIPPED: no rules defined
-# DEBUG-NEXT: .. imm index coverage check SKIPPED: no rules defined
+# DEBUG-NEXT: .. opcode {{[0-9]+}} is aliased to {{[0-9]+}}
+# DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
+# DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: G_VECREDUCE_SEQ_FADD (opcode {{[0-9]+}}): 3 type indices, 0 imm indices
 # DEBUG-NEXT: .. type index coverage check SKIPPED: user-defined predicate detected
 # DEBUG-NEXT: .. imm index coverage check SKIPPED: user-defined predicate detected

llvm/test/CodeGen/AArch64/arm64-trap.ll

@@ -1,5 +1,6 @@
 ; RUN: llc < %s -mtriple=arm64-eabi | FileCheck %s
 ; RUN: llc < %s -mtriple=arm64-eabi -global-isel | FileCheck %s
+
 define void @foo() nounwind {
 ; CHECK-LABEL: foo
 ; CHECK: brk #0x1