Fix Issue 22614 - [Windows] tmpnam() in runPreprocessor generates roo… (dlang#22615)

Fix Issue 22614 - [Windows] tmpnam() in runPreprocessor generates root-drive paths, fails with permission denied for non-admin users

Author: divyansharma001

compiler/src/dmd/link.d

@@ -958,9 +958,13 @@ public int runPreprocessor(Loc loc, const(char)[] cpp, const(char)[] filename, c
     version (Windows)
     {
         // generate unique temporary file name for preprocessed output
-        const(char)* tmpname = tmpnam(null);
-        assert(tmpname);
-        const(char)[] ifilename = tmpname[0 .. strlen(tmpname) + 1];
+        char[MAX_PATH] tempDir = void;
+        char[MAX_PATH] tempFile = void;
+        if (GetTempPathA(MAX_PATH, tempDir.ptr) == 0)
+            return STATUS_FAILED;
+        if (GetTempFileNameA(tempDir.ptr, "dmd", 0, tempFile.ptr) == 0)
+            return STATUS_FAILED;
+        const(char)[] ifilename = tempFile[0 .. strlen(tempFile.ptr) + 1];
         ifilename = xarraydup(ifilename);
         const(char)[] output = ifilename;