Added testcases for -Wdisabled-macro-expansion.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147473 91177308-0d34-0410-b5e6-96231b3b80d8

test/Preprocessor/warn-disabled-macro-expansion.c

+// RUN: %clang_cc1 %s -E -Wdisabled-macro-expansion -verify
+
+#define p p
+
+#define a b
+#define b a
+
+#define f(a) a
+
+#define g(b) a
+
+#define h(x) i(x)
+#define i(y) i(y)
+
+#define c(x) x(0)
+
+p // expected-warning {{recursive macro}}
+
+a // expected-warning {{recursive macro}}
+
+f(2)
+
+g(3) // expected-warning {{recursive macro}}
+
+h(0) // expected-warning {{recursive macro}}
+
+c(c) // expected-warning {{recursive macro}}