[vm] Fix clobbered THR/R14 in StoreReleaseLoadAcquire[1204] tests.

TEST=ci
Change-Id: I8297d630b47c422b420d3d3bc8d2a6876d446eaf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/397421
Commit-Queue: Ryan Macnak <[email protected]>
Reviewed-by: Alexander Aprelev <[email protected]>

Author: rmacnak-google

runtime/vm/compiler/assembler/assembler_x64_test.cc

@@ -6229,12 +6229,10 @@ IMMEDIATE_TEST(AddrImmRAXByte,
                __ popq(RAX))
 
 ASSEMBLER_TEST_GENERATE(StoreReleaseLoadAcquire, assembler) {
-  if (FLAG_target_thread_sanitizer) {
-    // On TSAN builds StoreRelease/LoadAcquire will do a runtime
-    // call to tell TSAN about our action.
-    __ MoveRegister(THR, CallingConventions::kArg2Reg);
-  }
-
+  // On TSAN builds StoreRelease/LoadAcquire will do a runtime
+  // call to tell TSAN about our action.
+  __ pushq(THR);
+  __ MoveRegister(THR, CallingConventions::kArg2Reg);
   __ pushq(RCX);
   __ xorq(RCX, RCX);
   __ pushq(RCX);
@@ -6299,6 +6297,7 @@ ASSEMBLER_TEST_GENERATE(StoreReleaseLoadAcquire, assembler) {
   __ LoadAcquireFromOffset(CallingConventions::kReturnReg, RSP, 0);
   __ popq(RCX);
   __ popq(RCX);
+  __ popq(THR);
   __ ret();
 }
 
@@ -6308,12 +6307,10 @@ ASSEMBLER_TEST_RUN(StoreReleaseLoadAcquire, test) {
 }
 
 ASSEMBLER_TEST_GENERATE(StoreReleaseLoadAcquire1024, assembler) {
-  if (FLAG_target_thread_sanitizer) {
-    // On TSAN builds StoreRelease/LoadAcquire will do a runtime
-    // call to tell TSAN about our action.
-    __ MoveRegister(THR, CallingConventions::kArg2Reg);
-  }
-
+  // On TSAN builds StoreRelease/LoadAcquire will do a runtime
+  // call to tell TSAN about our action.
+  __ pushq(THR);
+  __ MoveRegister(THR, CallingConventions::kArg2Reg);
   __ pushq(RCX);
   __ xorq(RCX, RCX);
   __ pushq(RCX);
@@ -6323,6 +6320,7 @@ ASSEMBLER_TEST_GENERATE(StoreReleaseLoadAcquire1024, assembler) {
   __ addq(RSP, Immediate(1024));
   __ popq(RCX);
   __ popq(RCX);
+  __ popq(THR);
   __ ret();
 }