[AVR] Let ArrayRef infer the array size (NFC)

[kazutakahirata]

No description provided.

[serge-sans-paille]

LGTM, thanks!

[llvm-ci]

LLVM Buildbot has detected a new failure on builder lldb-aarch64-ubuntu running on linaro-lldb-aarch64-ubuntu while building llvm at step 6 "test".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/287

Here is the relevant piece of the build log for the reference:

Step 6 (test) failure: build (failure)
...
UNSUPPORTED: lldb-api :: commands/expression/import-std-module/vector-of-vectors/TestVectorOfVectorsFromStdModule.py (100 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/import-std-module/vector/TestVectorFromStdModule.py (101 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/import-std-module/weak_ptr-dbg-info-content/TestDbgInfoContentWeakPtrFromStdModule.py (102 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/import-std-module/weak_ptr/TestWeakPtrFromStdModule.py (103 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/import_builtin_fileid/TestImportBuiltinFileID.py (104 of 1976)
PASS: lldb-api :: commands/expression/invalid-args/TestInvalidArgsExpression.py (105 of 1976)
PASS: lldb-api :: commands/expression/import_base_class_when_class_has_derived_member/TestImportBaseClassWhenClassHasDerivedMember.py (106 of 1976)
PASS: lldb-api :: commands/expression/inline-namespace/TestInlineNamespace.py (107 of 1976)
PASS: lldb-api :: commands/expression/ir-interpreter-phi-nodes/TestIRInterpreterPHINodes.py (108 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/multiline-completion/TestMultilineCompletion.py (109 of 1976)
XFAIL: lldb-api :: commands/expression/macros/TestMacros.py (110 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/multiline-navigation/TestMultilineNavigation.py (111 of 1976)
PASS: lldb-api :: commands/expression/memory-allocation/TestMemoryAllocSettings.py (112 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/namespace_local_var_same_name_cpp_and_c/TestNamespaceLocalVarSameNameCppAndC.py (113 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/namespace_local_var_same_name_obj_c/TestNamespaceLocalVarSameNameObjC.py (114 of 1976)
PASS: lldb-api :: commands/expression/issue_11588/Test11588.py (115 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/persist_objc_pointeetype/TestPersistObjCPointeeType.py (116 of 1976)
PASS: lldb-api :: commands/expression/namespace-alias/TestInlineNamespaceAlias.py (117 of 1976)
PASS: lldb-api :: commands/expression/ir-interpreter/TestIRInterpreter.py (118 of 1976)
PASS: lldb-api :: commands/expression/persistent_ptr_update/TestPersistentPtrUpdate.py (119 of 1976)
PASS: lldb-api :: commands/expression/options/TestExprOptions.py (120 of 1976)
PASS: lldb-api :: commands/expression/nested/TestNestedExpressions.py (121 of 1976)
PASS: lldb-api :: commands/expression/persistent_types/TestNestedPersistentTypes.py (122 of 1976)
PASS: lldb-api :: commands/expression/persistent_types/TestPersistentTypes.py (123 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/po_verbosity/TestPoVerbosity.py (124 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/po_persistent_result/TestPoPersistentResult.py (125 of 1976)
PASS: lldb-api :: commands/expression/no-deadlock/TestExprDoesntBlock.py (126 of 1976)
PASS: lldb-api :: commands/expression/persistent_variables/TestPersistentVariables.py (127 of 1976)
PASS: lldb-api :: commands/expression/pr52257/TestExprCrash.py (128 of 1976)
PASS: lldb-api :: commands/expression/persistent_result/TestPersistentResult.py (129 of 1976)
PASS: lldb-api :: commands/expression/radar_8638051/Test8638051.py (130 of 1976)
PASS: lldb-api :: commands/expression/pr35310/TestExprsBug35310.py (131 of 1976)
PASS: lldb-api :: commands/expression/radar_9531204/TestPrintfAfterUp.py (132 of 1976)
PASS: lldb-api :: commands/expression/radar_9673664/TestExprHelpExamples.py (133 of 1976)
PASS: lldb-api :: commands/expression/rdar42038760/TestScalarURem.py (134 of 1976)
PASS: lldb-api :: commands/expression/result_numbering/TestResultNumbering.py (135 of 1976)
PASS: lldb-api :: commands/expression/rdar44436068/Test128BitsInteger.py (136 of 1976)
PASS: lldb-api :: commands/expression/regression-access-function-template-in-record/TestRegressionAccessFunctionTemplateInRecord.py (137 of 1976)
PASS: lldb-api :: commands/expression/save_jit_objects/TestSaveJITObjects.py (138 of 1976)
PASS: lldb-api :: commands/expression/scoped_enums/TestScopedEnumType.py (139 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/two-files/TestObjCTypeQueryFromOtherCompileUnit.py (140 of 1976)
PASS: lldb-api :: commands/expression/test/TestExprs2.py (141 of 1976)
PASS: lldb-api :: commands/expression/static-initializers/TestStaticInitializers.py (142 of 1976)
PASS: lldb-api :: commands/expression/unicode-in-variable/TestUnicodeInVariable.py (143 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/vector_of_enums/TestVectorOfEnums.py (144 of 1976)
PASS: lldb-api :: commands/expression/expr-in-syscall/TestExpressionInSyscall.py (145 of 1976)
UNSUPPORTED: lldb-api :: commands/expression/weak_symbols/TestWeakSymbols.py (146 of 1976)
PASS: lldb-api :: commands/expression/top-level/TestTopLevelExprs.py (147 of 1976)
PASS: lldb-api :: commands/expression/unwind_expression/TestUnwindExpression.py (148 of 1976)