Test config macro canonicalization with CAS. (#11454)

This is a test accompanying llvm#159620, which fixes config macro canonicalization for scanning.

Specifically, without llvm#159620, when CAS is on, there are three variants of A. With llvm#159620, there should be only two variants. 

Part of work for rdar://136303612

Author: qiongsiwu

clang/test/ClangScanDeps/optimize-canonicalize-macros.m

@@ -7,6 +7,10 @@
 // RUN: clang-scan-deps -compilation-database %t/build/compile-commands.json \
 // RUN:   -j 1 -format experimental-full -optimize-args=canonicalize-macros > %t/deps.db
 // RUN: cat %t/deps.db | FileCheck %s -DPREFIX=%/t
+// RUN: clang-scan-deps -compilation-database %t/build/compile-commands.json \
+// RUN:   -j 1 -format experimental-include-tree-full -cas-path %t/cas \
+// RUN:   -optimize-args=canonicalize-macros > %t/deps_cas.db
+// RUN: cat %t/deps_cas.db | FileCheck %s --check-prefixes=CAS
 
 // This tests that we have two scanning module variants.
 // RUN: find %t/module-cache -name "*.pcm" | wc -l | grep 2
@@ -51,6 +55,41 @@
 // CHECK:      }
 
 
+// Check that when CAS is on, we still only have two variants of A.
+// CAS:      {
+// CAS-NEXT:   "modules": [
+// CAS-NEXT:     {
+// CAS-NEXT:       "cache-key": "{{.*}}",
+// CAS-NEXT:       "cas-include-tree-id": "{{.*}}",
+// CAS-NEXT:       "clang-module-deps": [],
+// CAS-NEXT:       "clang-modulemap-file":
+// CAS-NEXT:       "command-line": [
+// CAS:            ],
+// CAS-NEXT:       "context-hash": "{{.*}}",
+// CAS-NEXT:       "file-deps": [
+// CAS:            ],
+// CAS-NEXT:       "link-libraries": [],
+// CAS-NEXT:       "name": "A"
+// CAS-NEXT:     },
+// CAS-NEXT:     {
+// CAS-NEXT:       "cache-key": "{{.*}}",
+// CAS-NEXT:       "cas-include-tree-id": "{{.*}}",
+// CAS-NEXT:       "clang-module-deps": [],
+// CAS-NEXT:       "clang-modulemap-file":
+// CAS-NEXT:       "command-line": [
+// CAS:            ],
+// CAS-NEXT:       "context-hash": "{{.*}}",
+// CAS-NEXT:       "file-deps": [
+// CAS:            ],
+// CAS-NEXT:       "link-libraries": [],
+// CAS-NEXT:       "name": "A"
+// CAS-NEXT:     }
+// CAS-NEXT:   ],
+// CAS-NEXT:   "translation-units": [
+// CAS:        ]
+// CAS:      }
+
+
 //--- build/compile-commands.json.in
 
 [