Subzero. ARM32. Nonsfi.

Adds nonsfi support to the ARM32 backend.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4076
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1665263003 .
diff --git a/src/IceAssembler.cpp b/src/IceAssembler.cpp
index 28851f9..88c35d7 100644
--- a/src/IceAssembler.cpp
+++ b/src/IceAssembler.cpp
@@ -143,6 +143,12 @@
                          Buffer.size());
 }
 
+void Assembler::bindRelocOffset(RelocOffset *Offset) {
+  if (!getPreliminary()) {
+    Offset->setOffset(Buffer.getPosition());
+  }
+}
+
 void Assembler::emitIASBytes(GlobalContext *Ctx) const {
   Ostream &Str = Ctx->getStrEmit();
   intptr_t EndPosition = Buffer.size();