MIPS: Fixed two bugs related to double function calls.

These originated from 4dfb7f2e.
This fixes cctest test-api/ConversionNumber in soft-float mode.

BUG=
TEST=

Review URL: http://codereview.chromium.org//7068002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -3439,9 +3439,9 @@ void MathPowStub::Generate(MacroAssembler* masm) {
                           &call_runtime);
     __ push(ra);
     __ PrepareCallCFunction(3, scratch);
-    __ SetCallCDoubleArguments(double_base, double_exponent);
+    __ SetCallCDoubleArguments(double_base, exponent);
     __ CallCFunction(
-        ExternalReference::power_double_int_function(masm->isolate()), 4);
+        ExternalReference::power_double_int_function(masm->isolate()), 3);
     __ pop(ra);
     __ GetCFunctionDoubleResult(double_result);
     __ sdc1(double_result,

src/mips/macro-assembler-mips.cc

@@ -2651,9 +2651,9 @@ void MacroAssembler::CheckMap(Register obj,
 void MacroAssembler::GetCFunctionDoubleResult(const DoubleRegister dst) {
   CpuFeatures::Scope scope(FPU);
   if (IsMipsSoftFloatABI) {
-    Move(v0, v1, dst);
+    Move(dst, v0, v1);
   } else {
-    Move(f0, dst);  // Reg f0 is o32 ABI FP return value.
+    Move(dst, f0);  // Reg f0 is o32 ABI FP return value.
   }
 }