MIPS: Fixed illegal instruction use on Loongson in code for Math.random().

BUG=v8:2115
TEST=mjsunit/string-case,mjsunit/regress/regress-110509,mjsunit/math-floor

Review URL: https://chromiumcodereview.appspot.com/10383044
Patch from Akos Palfi <palfia@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11523 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -3225,7 +3225,7 @@ void LCodeGen::DoRandom(LRandom* instr) {
   // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
   __ And(a3, a1, Operand(0xFFFF));
   __ li(t0, Operand(18273));
-  __ mul(a3, a3, t0);
+  __ Mul(a3, a3, t0);
   __ srl(a1, a1, 16);
   __ Addu(a1, a3, a1);
   // Save state[0].
@@ -3234,7 +3234,7 @@ void LCodeGen::DoRandom(LRandom* instr) {
   // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
   __ And(a3, a0, Operand(0xFFFF));
   __ li(t0, Operand(36969));
-  __ mul(a3, a3, t0);
+  __ Mul(a3, a3, t0);
   __ srl(a0, a0, 16),
   __ Addu(a0, a3, a0);
   // Save state[1].