Added generation of the llvm 'sret' parameter attribute where applicable.

Fixed some wrong argument handling code when setting parameter attributes.
Updated the tango unittest script in the tango patch, does not work yet, all modules don't compile...

runtime/llvmdc.diff

@@ -94,6 +94,54 @@ Index: lib/common/tango/core/Thread.d
          version( X86_64 )
          {
  
+Index: lib/unittest.sh
+===================================================================
+--- lib/unittest.sh	(revision 3831)
++++ lib/unittest.sh	(working copy)
+@@ -18,8 +18,9 @@
+   --help: This message
+   --run-all: Reports result instead of breaking. Do not use this if you want to
+          run unittest runner through a debugger.
+-  dmd: Builds unittests for dmd
+-  gdc: Builds unittests for gdc
++  dmd:    Builds unittests for dmd
++  gdc:    Builds unittests for gdc
++  llvmdc: Builds unittests for llvmdc
+ 
+   <none>: Builds unittests for all known compilers.'
+   exit 0
+@@ -125,6 +126,9 @@
+         gdc)
+             GDC=1
+             ;;
++        llvmdc)
++            LLVMDC=1
++            ;;
+         *)
+             usage
+             ;;
+@@ -132,10 +136,11 @@
+     shift
+ done
+ 
+-if [ ! "$DMD" -a ! "$GDC" ]
++if [ ! "$DMD" -a ! "$GDC" -a ! "$LLVMDC" ]
+ then
+     DMD=1
+     GDC=1
++    LLVMDC=1
+ fi
+ 
+ if [ "$DMD" = "1" ]
+@@ -146,4 +151,7 @@
+ then
+     compile gdc runUnitTest_gdc
+ fi
+-
++if [ "$LLVMDC" = "1" ]
++then
++    compile llvmdc runUnitTest_llvmdc
++fi
 Index: lib/gc/basic/gcx.d
 ===================================================================
 --- lib/gc/basic/gcx.d	(revision 3831)