[clang][deps] NFC: Make PCH test more debuggable

Overwriting CDB files made it difficult to debug earlier clang-scan-deps invocations. This commit creates separate files for each.

Author: jansvoboda11

clang/test/ClangScanDeps/modules-pch.c

@@ -7,8 +7,8 @@
 
 // Scan dependencies of the PCH:
 //
-// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_pch.json > %t/cdb.json
-// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
+// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_pch.json > %t/cdb_pch.json
+// RUN: clang-scan-deps -compilation-database %t/cdb_pch.json -format experimental-full \
 // RUN:   -module-files-dir %t/build > %t/result_pch.json
 // RUN: cat %t/result_pch.json | sed 's:\\\\\?:/:g' | FileCheck %s -DPREFIX=%/t -check-prefix=CHECK-PCH
 //
@@ -94,8 +94,8 @@
 
 // Scan dependencies of the TU:
 //
-// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu.json > %t/cdb.json
-// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
+// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu.json > %t/cdb_tu.json
+// RUN: clang-scan-deps -compilation-database %t/cdb_tu.json -format experimental-full \
 // RUN:   -module-files-dir %t/build > %t/result_tu.json
 // RUN: cat %t/result_tu.json | sed 's:\\\\\?:/:g' | FileCheck %s -DPREFIX=%/t -check-prefix=CHECK-TU
 //
@@ -142,8 +142,8 @@
 
 // Scan dependencies of the TU that has common modules with the PCH:
 //
-// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu_with_common.json > %t/cdb.json
-// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full \
+// RUN: sed "s|DIR|%/t|g" %S/Inputs/modules-pch/cdb_tu_with_common.json > %t/cdb_tu_with_common.json
+// RUN: clang-scan-deps -compilation-database %t/cdb_tu_with_common.json -format experimental-full \
 // RUN:   -module-files-dir %t/build > %t/result_tu_with_common.json
 // RUN: cat %t/result_tu_with_common.json | sed 's:\\\\\?:/:g' | FileCheck %s -DPREFIX=%/t -check-prefix=CHECK-TU-WITH-COMMON
 //