[CodeGen] Use getCharWidth() more consistently in CGRecordLowering. NFC

When using getByteArrayType the requested size is calculated in
char units, but the type used for the array was hardcoded to the
Int8Ty. This patch is using getCharWIdth a bit more consistently
by using getIntNTy in combination with getCharWidth, instead
of explictly using getInt8Ty.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D94977

Author: bjope

clang/lib/CodeGen/CGRecordLayoutBuilder.cpp

@@ -127,15 +127,20 @@ struct CGRecordLowering {
 
   /// Wraps llvm::Type::getIntNTy with some implicit arguments.
   llvm::Type *getIntNType(uint64_t NumBits) {
+    unsigned AlignedBits = llvm::alignTo(NumBits, Context.getCharWidth());
+    return llvm::Type::getIntNTy(Types.getLLVMContext(), AlignedBits);
+  }
+  /// Get the LLVM type sized as one character unit.
+  llvm::Type *getCharType() {
     return llvm::Type::getIntNTy(Types.getLLVMContext(),
-                                 (unsigned)llvm::alignTo(NumBits, 8));
+                                 Context.getCharWidth());
   }
-  /// Gets an llvm type of size NumBytes and alignment 1.
-  llvm::Type *getByteArrayType(CharUnits NumBytes) {
-    assert(!NumBytes.isZero() && "Empty byte arrays aren't allowed.");
-    llvm::Type *Type = llvm::Type::getInt8Ty(Types.getLLVMContext());
-    return NumBytes == CharUnits::One() ? Type :
-        (llvm::Type *)llvm::ArrayType::get(Type, NumBytes.getQuantity());
+  /// Gets an llvm type of size NumChars and alignment 1.
+  llvm::Type *getByteArrayType(CharUnits NumChars) {
+    assert(!NumChars.isZero() && "Empty byte arrays aren't allowed.");
+    llvm::Type *Type = getCharType();
+    return NumChars == CharUnits::One() ? Type :
+        (llvm::Type *)llvm::ArrayType::get(Type, NumChars.getQuantity());
   }
   /// Gets the storage type for a field decl and handles storage
   /// for itanium bitfields that are smaller than their declared type.