[SYCL] Fix directory field of DIFile. (#8838)

The directory should be the current working directory of the compilation
command that produced the DICompileUnit.
In other words, it should be the directory where the app is running and
not the directory where the source app resides.

Author: zahiraam

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -667,11 +667,8 @@ void CGDebugInfo::CreateCompileUnit() {
   if (CSKind)
     CSInfo.emplace(*CSKind, Checksum);
 
-  if (!CGM.getCodeGenOpts().SYCLUseMainFileName)
-    MainFileDir = getCurrentDirname();
-
   llvm::DIFile *CUFile =
-      DBuilder.createFile(remapDIPath(MainFileName), remapDIPath(MainFileDir),
+      DBuilder.createFile(remapDIPath(MainFileName), remapDIPath(getCurrentDirname()),
                           CSInfo, getSource(SM, SM.getMainFileID()));
 
   StringRef Sysroot, SDK;

clang/test/CodeGenSYCL/debug-info-checksum-temp-name.cpp

@@ -24,7 +24,6 @@
 //
 // CHECK: !DICompileUnit({{.*}} file: ![[#FILE:]]
 // CHECK: ![[#FILE]] = !DIFile(filename: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL{{.+}}Inputs{{.+}}debug-info-checksum.cpp"
-// CHECK-SAME: directory: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL{{.+}}Inputs"
 // CHECK-SAME: checksumkind: CSK_MD5, checksum: "f1fb5d68350b47d90a53968ac8c40529"
 
 #include "Inputs/debug-info-checksum.cpp"

clang/test/CodeGenSYCL/debug-info-file-checksum.cpp

@@ -26,12 +26,10 @@
 
 // COMP1: !DICompileUnit({{.*}} file: ![[#FILE1:]]
 // COMP1: ![[#FILE1]] = !DIFile(filename: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL{{.+}}Inputs{{.+}}checksum.cpp"
-// COMP1-SAME: directory: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL/Inputs"
 // COMP1-SAME: checksumkind: CSK_MD5, checksum: "259269f735d83ec32c46a11352458493")
 
 // COMP2: !DICompileUnit({{.*}} file: ![[#FILE2:]]
 // COMP2: ![[#FILE2]] = !DIFile(filename: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL{{.+}}Inputs{{.+}}checksum.cpp"
-// COMP2: directory: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL/Output"
 // COMP2-SAME: checksumkind: CSK_MD5, checksum: "259269f735d83ec32c46a11352458493")
 
 // TODO: Fails on windows because of the use of append-file command that returns

clang/test/CodeGenSYCL/debug-info-file-prefix-map.cpp

@@ -14,8 +14,7 @@
 
 // CHECK: distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: ![[#FILE1:]]
 // CHECK-NEXT: ![[#FILE1]] = !DIFile(filename: "debug-info-file-prefix-map.cpp"
-// CHECK-SAME: directory: "{{.*}}clang{{.+}}test{{.+}}CodeGenSYCL"
-// CHECK: ![[#FILE2:]] = !DIFile(filename: "debug-info-file-prefix-map.cpp", directory: "")
+// CHECK: ![[#FILE2:]] = !DIFile(filename: "debug-info-file-prefix-map.cpp"
 // CHECK: !DIDerivedType(tag: DW_TAG_typedef, name: "__builtin_va_list", file: ![[#FILE2]]
 
 void a(__builtin_va_list);