Make FlushICache part of Assembler(Base) and take Isolate as parameter.

src/ia32/assembler-ia32.h

Index: src/ia32/assembler-ia32.h
diff --git a/src/ia32/assembler-ia32.h b/src/ia32/assembler-ia32.h
index 57987bc7513c6337ae1dff885ddb9fba162f6430..b1f128b8d9ac92d2f0fe3defae6df2eb5e295105 100644
--- a/src/ia32/assembler-ia32.h
+++ b/src/ia32/assembler-ia32.h
@@ -489,6 +489,9 @@ class Assembler : public AssemblerBase {
   static const int kGap = 32;
 
  public:
+  using AssemblerBase::FlushICache;
+  using AssemblerBase::FlushICacheWithoutIsolate;
+
   // Create an assembler. Instructions and relocation information are emitted
   // into a buffer, with the instructions starting from the beginning and the
   // relocation information starting from the end of the buffer. See CodeDesc