X87: [builtins] Introduce proper Float64Log2 and Float64Log10 operators.

src/compiler/x87/code-generator-x87.cc

Index: src/compiler/x87/code-generator-x87.cc
diff --git a/src/compiler/x87/code-generator-x87.cc b/src/compiler/x87/code-generator-x87.cc
index 2fc009c4360f875530d9ff7284a0453abb7dc87d..f304192618b2f825c45d45ac2d971dc246834e34 100644
--- a/src/compiler/x87/code-generator-x87.cc
+++ b/src/compiler/x87/code-generator-x87.cc
@@ -760,6 +760,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kIeee754Float64Log1p:
       ASSEMBLE_IEEE754_UNOP(log1p);
       break;
+    case kIeee754Float64Log2:
+      ASSEMBLE_IEEE754_UNOP(log2);
+      break;
+    case kIeee754Float64Log10:
+      ASSEMBLE_IEEE754_UNOP(log10);
+      break;
     case kX87Add:
       if (HasImmediateInput(instr, 1)) {
         __ add(i.InputOperand(0), i.InputImmediate(1));