[gardening] Fix offset calculation on riscv for newly added fields.

Follow-up to 2d7c7b0
Fixes #61402
TEST=ci

Change-Id: Ifeb8a3e9cfa6080b65350a6c9fbce1302ae59844
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/446742
Reviewed-by: Ryan Macnak <[email protected]>
Commit-Queue: Alexander Aprelev <[email protected]>

Author: aam

runtime/vm/compiler/asm_intrinsifier_riscv.cc

@@ -1997,13 +1997,13 @@ void AsmIntrinsifier::IntrinsifyRegExpExecuteMatch(Assembler* assembler,
 
 void AsmIntrinsifier::UserTag_defaultTag(Assembler* assembler,
                                          Label* normal_ir_body) {
-  __ lx(A0, Address(THR, target::Thread::default_tag_offset()));
+  __ LoadFromOffset(A0, THR, target::Thread::default_tag_offset());
   __ ret();
 }
 
 void AsmIntrinsifier::Profiler_getCurrentTag(Assembler* assembler,
                                              Label* normal_ir_body) {
-  __ lx(A0, Address(THR, target::Thread::current_tag_offset()));
+  __ LoadFromOffset(A0, THR, target::Thread::current_tag_offset());
   __ ret();
 }