[AArch64][GlobalISel] Added support for neon left shift intrinsics on single-element vector types (#170827)

Previously, the left shift family of intrinsics would fail to lower for
<1 x i64> / <1 x i32> vector types, as IRTranslation lowers these to
scalars. Marking these intrinsics as only using fp operands ensures the
RegBankSelect phase places the vector on an fpr bank, instead of a gpr
bank.

Author: JoshdRod

llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp

@@ -483,6 +483,14 @@ static bool isFPIntrinsic(const MachineRegisterInfo &MRI,
   case Intrinsic::aarch64_neon_sqadd:
   case Intrinsic::aarch64_neon_sqsub:
   case Intrinsic::aarch64_crypto_sha1h:
+  case Intrinsic::aarch64_neon_srshl:
+  case Intrinsic::aarch64_neon_urshl:
+  case Intrinsic::aarch64_neon_sqshl:
+  case Intrinsic::aarch64_neon_uqshl:
+  case Intrinsic::aarch64_neon_sqrshl:
+  case Intrinsic::aarch64_neon_uqrshl:
+  case Intrinsic::aarch64_neon_ushl:
+  case Intrinsic::aarch64_neon_sshl:
   case Intrinsic::aarch64_crypto_sha1c:
   case Intrinsic::aarch64_crypto_sha1p:
   case Intrinsic::aarch64_crypto_sha1m:

llvm/test/CodeGen/AArch64/arm64-int-neon.ll

@@ -3,15 +3,7 @@
 ; RUN: llc < %s -mtriple aarch64-unknown-unknown -global-isel -global-isel-abort=2 -mattr=+fprcvt,+fullfp16 2>&1 | FileCheck %s --check-prefixes=CHECK,CHECK-GI
 
 
-; CHECK-GI:       warning: Instruction selection used fallback path for test_sqrshl_s32
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_sqrshl_s64
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_sqshl_s32
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_sqshl_s64
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqrshl_s32
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqrshl_s64
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqshl_s32
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqshl_s64
-; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqadd_s32
+; CHECK-GI:  warning: Instruction selection used fallback path for test_uqadd_s32
 ; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqadd_s64
 ; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqsub_s32
 ; CHECK-GI-NEXT:  warning: Instruction selection used fallback path for test_uqsub_s64