Fix the regression introduced when added the 32 bit support (broken
struct UPC pointer to shared on 64 bit targets).

	lib/CodeGen/CGExpr.cpp: Remove unused variables.
	lib/CodeGen/CGExprUPC.cpp: Create proper conatines for 32 bit sizes.
	lib/Frontend/CompilerInvocation.cpp: Set the proper UPC struct pointer to shared
		fields sizes.
	lib/Frontend/InitPreprocessor.cpp: Code simplification as thread/phase sizes
		are already set correctly.