Elaborate PChainConstructor calls.

It is better to leave the handling of PChainConstructor calls to
the elaboration, instead of stripping them out early. This allows
for handling the arguments of the chain constructor in the correct
scope.

PFunction.cc

@@ -21,6 +21,7 @@
 # include "PTask.h"
 # include "Statement.h"
 # include <cassert>
+# include "ivl_assert.h"
 
 PFunction::PFunction(perm_string name, LexicalScope*parent, bool is_auto__)
 : PTaskFunc(name, parent), statement_(0)
@@ -33,13 +34,37 @@ PFunction::~PFunction()
 {
 }
 
-void PFunction::set_statement(Statement*s, bool rewrite_ok)
+void PFunction::set_statement(Statement*s)
 {
       assert(s != 0);
-      assert(statement_ == 0 || rewrite_ok&&statement_);
+      assert(statement_ == 0);
       statement_ = s;
 }
 
+void PFunction::push_statement_front(Statement*stmt)
+{
+	// This can only happen after the statement is initially set.
+      ivl_assert(*this, statement_);
+
+	// Get the PBlock of the statement. If it is not a PBlock,
+	// then create one to wrap the existing statement and the new
+	// statement that we're pushing.
+      PBlock*blk = dynamic_cast<PBlock*> (statement_);
+      if (blk == 0) {
+	    PBlock*tmp = new PBlock(PBlock::BL_SEQ);
+	    tmp->set_line(*this);
+	    vector<Statement*>tmp_list(1);
+	    tmp_list[0] = statement_;
+	    tmp->set_statement(tmp_list);
+
+	    statement_ = tmp;
+	    blk = tmp;
+      }
+
+	// Now do the push.
+      blk->push_statement_front(stmt);
+}
+
 void PFunction::set_return(const data_type_t*t)
 {
       return_type_ = t;