VM: Simplify assembler test by removing unused parameter.

runtime/vm/assembler_mips_test.cc

Index: runtime/vm/assembler_mips_test.cc
diff --git a/runtime/vm/assembler_mips_test.cc b/runtime/vm/assembler_mips_test.cc
index a0a3a4187d16aee6a5f36f11036181f053c31f6c..ec943509e093cef8b83eed8ac6cbc6ed486374f6 100644
--- a/runtime/vm/assembler_mips_test.cc
+++ b/runtime/vm/assembler_mips_test.cc
@@ -2083,24 +2083,20 @@ ASSEMBLER_TEST_RUN(Cop1CvtSD, test) {
 
 // Called from assembler_test.cc.
 // RA: return address.
-// A0: context.
-// A1: value.
-// A2: growable array.
-// A3: current thread.
+// A0: value.
+// A1: growable array.
+// A2: current thread.
 ASSEMBLER_TEST_GENERATE(StoreIntoObject, assembler) {
-  __ addiu(SP, SP, Immediate(-3 * kWordSize));
-  __ sw(THR, Address(SP, 2 * kWordSize));
-  __ sw(CTX, Address(SP, 1 * kWordSize));
+  __ addiu(SP, SP, Immediate(-2 * kWordSize));
+  __ sw(THR, Address(SP, 1 * kWordSize));
   __ sw(RA, Address(SP, 0 * kWordSize));
-  __ mov(CTX, A0);
-  __ mov(THR, A3);
-  __ StoreIntoObject(A2,
-                     FieldAddress(A2, GrowableObjectArray::data_offset()),
-                     A1);
+  __ mov(THR, A2);
+  __ StoreIntoObject(A1,
+                     FieldAddress(A1, GrowableObjectArray::data_offset()),
+                     A0);
   __ lw(RA, Address(SP, 0 * kWordSize));
-  __ lw(CTX, Address(SP, 1 * kWordSize));
-  __ lw(THR, Address(SP, 2 * kWordSize));
-  __ addiu(SP, SP, Immediate(3 * kWordSize));
+  __ lw(THR, Address(SP, 1 * kWordSize));
+  __ addiu(SP, SP, Immediate(2 * kWordSize));
   __ Ret();
 }