XFAIL Hexagon until more codegen in place.

[rfoos]

Summary

Hexagon is being updated, but there is not enough to pass these tests.
These sections are now on top of Colin's list.

test/ASTMerge/codegen-body.c

+// XFAIL: hexagon
 // RUN: %clang_cc1 -emit-pch -o %t.1.ast %S/Inputs/body1.c
 // RUN: %clang_cc1 -emit-pch -o %t.2.ast %S/Inputs/body2.c
 // RUN: %clang_cc1 -emit-obj -o /dev/null -ast-merge %t.1.ast -ast-merge %t.2.ast %s
 // expected-no-diagnostics
 

test/CodeGenCXX/copy-constructor-synthesis-2.cpp

+// XFAIL: hexagon
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++11 -emit-llvm -o - %s | FileCheck %s
 
 union PR23373 {
   PR23373(PR23373&) = default;
   PR23373 &operator=(PR23373&) = default;
   int n;
   float f;
 };