[SYCLomatic] Fix the unreduced type processing in dpct when input source code has build error on using "auto" for type (#2826)

Signed-off-by: Chen, Sheng S <sheng.s.chen@intel.com>

Author: ShengchenJ

clang/include/clang/AST/ASTContext.h

@@ -2511,7 +2511,12 @@ class ASTContext : public RefCountedBase<ASTContext> {
   CharUnits getTypeSizeInChars(const Type *T) const;
 
   std::optional<CharUnits> getTypeSizeInCharsIfKnown(QualType Ty) const {
+#ifdef SYCLomatic_CUSTOMIZATION
+    if (Ty->isIncompleteType() || Ty->isDependentType() ||
+        Ty->isUndeducedType())
+#else
     if (Ty->isIncompleteType() || Ty->isDependentType())
+#endif
       return std::nullopt;
     return getTypeSizeInChars(Ty);
   }

clang/test/dpct/internal_error/auto_deduce_fail_in_kernel.cu

@@ -0,0 +1,11 @@
+// RUN: dpct --out-root %T %s --cuda-include-path="%cuda-path/include" > %T/auto_deduce_output.txt 2>&1 || true
+// RUN: grep "dpct internal error" %T/auto_deduce_output.txt | wc -l > %T/wc_auto_deduce_output.txt || true
+// RUN: FileCheck %s --match-full-lines --input-file %T/wc_auto_deduce_output.txt
+// RUN: rm -rf %T
+
+// CHECK: 0
+
+__device__ void test_auto() {
+
+  auto tid = get_tid();
+}