[RISCV] Add test for spilling and reloading a GPRPair for Zdinx+RV32. NFC (#139983)

I couldn't find any existing coverage for PseudoRV32ZdinxSD and
PseudoRV32ZdinxLD being emitted from
storeRegToStackSlot/loadRegFromStackSlot.

Author: topperc

llvm/test/CodeGen/RISCV/zdinx-spill.ll

@@ -0,0 +1,71 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=riscv32 -mattr=+zdinx -verify-machineinstrs -stop-after=prologepilog | FileCheck %s
+
+declare void @bar()
+
+define double @foo(double %x) nounwind {
+  ; CHECK-LABEL: name: foo
+  ; CHECK: bb.0 (%ir-block.0):
+  ; CHECK-NEXT:   liveins: $x10, $x11, $x8, $x9, $x18, $x19, $x20, $x21, $x22, $x23, $x24, $x25, $x26, $x27
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   $x2 = frame-setup ADDI $x2, -64
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION def_cfa_offset 64
+  ; CHECK-NEXT:   frame-setup SW killed $x8, $x2, 60 :: (store (s32) into %stack.1)
+  ; CHECK-NEXT:   frame-setup SW killed $x9, $x2, 56 :: (store (s32) into %stack.2)
+  ; CHECK-NEXT:   frame-setup SW killed $x18, $x2, 52 :: (store (s32) into %stack.3)
+  ; CHECK-NEXT:   frame-setup SW killed $x19, $x2, 48 :: (store (s32) into %stack.4)
+  ; CHECK-NEXT:   frame-setup SW killed $x20, $x2, 44 :: (store (s32) into %stack.5)
+  ; CHECK-NEXT:   frame-setup SW killed $x21, $x2, 40 :: (store (s32) into %stack.6)
+  ; CHECK-NEXT:   frame-setup SW killed $x22, $x2, 36 :: (store (s32) into %stack.7)
+  ; CHECK-NEXT:   frame-setup SW killed $x23, $x2, 32 :: (store (s32) into %stack.8)
+  ; CHECK-NEXT:   frame-setup SW killed $x24, $x2, 28 :: (store (s32) into %stack.9)
+  ; CHECK-NEXT:   frame-setup SW killed $x25, $x2, 24 :: (store (s32) into %stack.10)
+  ; CHECK-NEXT:   frame-setup SW killed $x26, $x2, 20 :: (store (s32) into %stack.11)
+  ; CHECK-NEXT:   frame-setup SW killed $x27, $x2, 16 :: (store (s32) into %stack.12)
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x8, -4
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x9, -8
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x18, -12
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x19, -16
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x20, -20
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x21, -24
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x22, -28
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x23, -32
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x24, -36
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x25, -40
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x26, -44
+  ; CHECK-NEXT:   frame-setup CFI_INSTRUCTION offset $x27, -48
+  ; CHECK-NEXT:   renamable $x10_x11 = nofpexcept FADD_D_IN32X killed renamable $x10_x11, renamable $x10_x11, 7, implicit $frm
+  ; CHECK-NEXT:   PseudoRV32ZdinxSD killed renamable $x10_x11, $x2, 8 :: (store (s64) into %stack.0, align 4)
+  ; CHECK-NEXT:   INLINEASM &"", 1 /* sideeffect attdialect */, 12 /* clobber */, implicit-def dead early-clobber $x6, 12 /* clobber */, implicit-def dead early-clobber $x7, 12 /* clobber */, implicit-def dead early-clobber $x8, 12 /* clobber */, implicit-def dead early-clobber $x9, 12 /* clobber */, implicit-def dead early-clobber $x10, 12 /* clobber */, implicit-def dead early-clobber $x11, 12 /* clobber */, implicit-def dead early-clobber $x12, 12 /* clobber */, implicit-def dead early-clobber $x13, 12 /* clobber */, implicit-def dead early-clobber $x14, 12 /* clobber */, implicit-def dead early-clobber $x15, 12 /* clobber */, implicit-def dead early-clobber $x16, 12 /* clobber */, implicit-def dead early-clobber $x17, 12 /* clobber */, implicit-def dead early-clobber $x18, 12 /* clobber */, implicit-def dead early-clobber $x19, 12 /* clobber */, implicit-def dead early-clobber $x20, 12 /* clobber */, implicit-def dead early-clobber $x21, 12 /* clobber */, implicit-def dead early-clobber $x22, 12 /* clobber */, implicit-def dead early-clobber $x23, 12 /* clobber */, implicit-def dead early-clobber $x24, 12 /* clobber */, implicit-def dead early-clobber $x25, 12 /* clobber */, implicit-def dead early-clobber $x26, 12 /* clobber */, implicit-def dead early-clobber $x27, 12 /* clobber */, implicit-def dead early-clobber $x28, 12 /* clobber */, implicit-def dead early-clobber $x29, 12 /* clobber */, implicit-def dead early-clobber $x31
+  ; CHECK-NEXT:   renamable $x10_x11 = PseudoRV32ZdinxLD $x2, 8 :: (load (s64) from %stack.0, align 4)
+  ; CHECK-NEXT:   $x8 = frame-destroy LW $x2, 60 :: (load (s32) from %stack.1)
+  ; CHECK-NEXT:   $x9 = frame-destroy LW $x2, 56 :: (load (s32) from %stack.2)
+  ; CHECK-NEXT:   $x18 = frame-destroy LW $x2, 52 :: (load (s32) from %stack.3)
+  ; CHECK-NEXT:   $x19 = frame-destroy LW $x2, 48 :: (load (s32) from %stack.4)
+  ; CHECK-NEXT:   $x20 = frame-destroy LW $x2, 44 :: (load (s32) from %stack.5)
+  ; CHECK-NEXT:   $x21 = frame-destroy LW $x2, 40 :: (load (s32) from %stack.6)
+  ; CHECK-NEXT:   $x22 = frame-destroy LW $x2, 36 :: (load (s32) from %stack.7)
+  ; CHECK-NEXT:   $x23 = frame-destroy LW $x2, 32 :: (load (s32) from %stack.8)
+  ; CHECK-NEXT:   $x24 = frame-destroy LW $x2, 28 :: (load (s32) from %stack.9)
+  ; CHECK-NEXT:   $x25 = frame-destroy LW $x2, 24 :: (load (s32) from %stack.10)
+  ; CHECK-NEXT:   $x26 = frame-destroy LW $x2, 20 :: (load (s32) from %stack.11)
+  ; CHECK-NEXT:   $x27 = frame-destroy LW $x2, 16 :: (load (s32) from %stack.12)
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x8
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x9
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x18
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x19
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x20
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x21
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x22
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x23
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x24
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x25
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x26
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION restore $x27
+  ; CHECK-NEXT:   $x2 = frame-destroy ADDI $x2, 64
+  ; CHECK-NEXT:   frame-destroy CFI_INSTRUCTION def_cfa_offset 0
+  ; CHECK-NEXT:   PseudoRET implicit $x10, implicit $x11
+  %a = fadd double %x, %x
+  call void asm sideeffect "", "~{x6},~{x7},~{x8},~{x9},~{x10},~{x11},~{x12},~{x13},~{x14},~{x15},~{x16},~{x17},~{x18},~{x19},~{x20},~{x21},~{x22},~{x23},~{x24},~{x25},~{x26},~{x27},~{x28},~{x29},~{xr0},~{x31}"()
+  ret double %a
+}