Increase the macro id cache to look up several recent entries, not just the last one. This is important in insane cases like the one dannyb sent me recently:

#define F0(a) void a(){}
#define F1(a) F0(a0) F0(a1) F0(a2) F0(a3) F0(a4) F0(a5) F0(a6) F0(a7)
#define F2(a) F1(a0) F1(a1) F1(a2) F1(a3) F1(a4) F1(a5) F1(a6) F1(a7)
#define F3(a) F2(a0) F2(a1) F2(a2) F2(a3) F2(a4) F2(a5) F2(a6) F2(a7)
#define F4(a) F3(a0) F3(a1) F3(a2) F3(a3) F3(a4) F3(a5) F3(a6) F3(a7)
#define F5(a) F4(a0) F4(a1) F4(a2) F4(a3) F4(a4) F4(a5) F4(a6) F4(a7)
#define F6(a) F5(a0) F5(a1) F5(a2) F5(a3) F5(a4) F5(a5) F5(a6) F5(a7)
F6(f)

cpp is great. :)

llvm-svn: 40715