Revert "Fix up MCPlusBuilder.cpp to account for W0_HI on AArch64"

This reverts commit 576865a.

Depends on #114827 that was reverted.

Author: maksfb

bolt/unittests/Core/MCPlusBuilder.cpp

@@ -90,15 +90,14 @@ INSTANTIATE_TEST_SUITE_P(AArch64, MCPlusBuilderTester,
                          ::testing::Values(Triple::aarch64));
 
 TEST_P(MCPlusBuilderTester, AliasX0) {
-  uint64_t AliasesX0[] = {AArch64::W0,    AArch64::W0_HI,
-                          AArch64::X0,    AArch64::W0_W1,
+  uint64_t AliasesX0[] = {AArch64::W0, AArch64::X0, AArch64::W0_W1,
                           AArch64::X0_X1, AArch64::X0_X1_X2_X3_X4_X5_X6_X7};
   size_t AliasesX0Count = sizeof(AliasesX0) / sizeof(*AliasesX0);
   testRegAliases(Triple::aarch64, AArch64::X0, AliasesX0, AliasesX0Count);
 }
 
 TEST_P(MCPlusBuilderTester, AliasSmallerX0) {
-  uint64_t AliasesX0[] = {AArch64::W0, AArch64::W0_HI, AArch64::X0};
+  uint64_t AliasesX0[] = {AArch64::W0, AArch64::X0};
   size_t AliasesX0Count = sizeof(AliasesX0) / sizeof(*AliasesX0);
   testRegAliases(Triple::aarch64, AArch64::X0, AliasesX0, AliasesX0Count, true);
 }