Work on support for pthreads.
Move TLD declarations to the global scope.  Fixes #100.
Make sure that we create the correct typedefs for incomplete arrays.  Fixes #101.
Fix anonymous record issues.  Fixes #102.
All DeclRefs require dynamic initialization in pthreads mode.  Fixes #103.
Fix issue 107 and factor TLD_ADDR logic
Minor cleanup to previous commit
Complete the fix for issue 103 by using UPCR_TLD_ADDR() on LHS of initializers of TLD variables
Add support for "-pthread" switch on upc2c command line. TLD macros
are generated only if this switch is present.
Remove redundant UPCTLDEnable checks

This reverts two hunks from Nenad's recent addition of support for
a -pthreads flag.  As confirmed with Nenad by email, these two checks
were redundant given the others that remain.
Disable TLD warping for variables with extern.
Make sure that static variable names are mangles when they are promoted the the global scope.  Fixes #100.
Move type declarations to the global scope.
Fix problems with va_list, that cause an assertion failure.
Make sure that decls are inserted in the correct declcontext.
Switch to the correct declcontext before entering a record definition.
Override the actual implementation function instead of the wrapper.  Fixes #110.