[RISCV] Precommit testcase to show wrong result of make-compressible optimization

[kito-cheng]

Summary

Use following example to demo what happened now:

li      a1, 1
sd      a1, 800(a0)
sd      a0, 808(a0) # Store base address into base + offset
li      a1, 2
sd      a1, 816(a0)

Current will optimizate into:

li      a1, 1
addi    a2, a0, 768
sd      a1, 32(a2)
sd      a2, 40(a2) # Wrong replacement for the source register.
li      a1, 2
sd      a1, 48(a2)

llvm/test/CodeGen/RISCV/make-compressible-for-store-address.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -o - %s -mtriple=riscv64 -mattr=+c -simplify-mir \
+# RUN:   -run-pass=riscv-make-compressible | FileCheck %s
+--- |
+  define void @foo(ptr noundef %ptr) #0 {
+  entry:
+    %0 = ptrtoint ptr %ptr to i64
+    %1 = getelementptr inbounds i64, ptr %ptr, i64 100
+    store i64 1, ptr %1, align 8
+    %2 = getelementptr inbounds i64, ptr %ptr, i64 101
+    store i64 %0, ptr %2, align 8
+    %3 = getelementptr inbounds i64, ptr %ptr, i64 102
+    store i64 2, ptr %3, align 8
+    ret void
+  }
+
+  attributes #0 = { minsize }
+
+...
+---
+name:            foo
+alignment:       2
+tracksRegLiveness: true
+liveins:
+  - { reg: '$x10' }
+body:             |
+  bb.0.entry:
+    liveins: $x10
+
+    ; CHECK-LABEL: name: foo
+    ; CHECK: liveins: $x10
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: renamable $x11 = ADDI $x0, 1
+    ; CHECK-NEXT: $x12 = ADDI $x10, 768
+    ; CHECK-NEXT: SD killed renamable $x11, $x12, 32 :: (store (s64) into %ir.1)
+    ; CHECK-NEXT: SD $x12, $x12, 40 :: (store (s64) into %ir.2)
+    ; CHECK-NEXT: renamable $x11 = ADDI $x0, 2
+    ; CHECK-NEXT: SD killed renamable $x11, killed $x12, 48 :: (store (s64) into %ir.3)
+    ; CHECK-NEXT: PseudoRET
+    renamable $x11 = ADDI $x0, 1
+    SD killed renamable $x11, renamable $x10, 800 :: (store (s64) into %ir.1)
+    SD renamable $x10, renamable $x10, 808 :: (store (s64) into %ir.2)
+    renamable $x11 = ADDI $x0, 2
+    SD killed renamable $x11, killed renamable $x10, 816 :: (store (s64) into %ir.3)
+    PseudoRET
+
+...