rtems: add _clang-format in root

Updates #3860.

_clang-format

@@ -0,0 +1,159 @@
+---
+Language:        Cpp
+AccessModifierOffset: -2
+AlignAfterOpenBracket: true
+AlignArrayOfStructures: None
+AlignConsecutiveMacros: true
+AlignConsecutiveAssignments: None
+AlignConsecutiveDeclarations:
+  Enabled: true
+  AcrossEmptyLines: false
+  AcrossComments: true
+AlignEscapedNewlines: Left
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortLambdasOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: MultiLine
+BinPackArguments: false
+BinPackLongBracedList: false
+BinPackParameters: OnePerLine
+BreakAfterOpenBracketBracedList: true
+BreakAfterOpenBracketFunction: true
+BreakAfterOpenBracketIf: true
+BreakAfterOpenBracketLoop: true
+BreakAfterOpenBracketSwitch: true
+BreakBeforeBraces: Custom
+BreakBeforeCloseBracketBracedList: true
+BreakBeforeCloseBracketFunction: true
+BreakBeforeCloseBracketIf: true
+BreakBeforeCloseBracketLoop: true
+BreakBeforeCloseBracketSwitch: true
+BreakBinaryOperations: Never
+BraceWrapping:
+  AfterCaseLabel:  false
+  AfterClass:      false
+  AfterControlStatement: false
+  AfterEnum:       false
+  AfterFunction:   true
+  AfterNamespace:  false
+  AfterObjCDeclaration: false
+  AfterStruct:     false
+  AfterUnion:      false
+  AfterExternBlock: false
+  BeforeCatch:     false
+  BeforeElse:      false
+  IndentBraces:    false
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: None
+BreakBeforeInheritanceComma: false
+BreakInheritanceList: BeforeColon
+BreakBeforeInlineASMColon: Always
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: false
+ColumnLimit:     79
+CommentPragmas:  '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 2
+ContinuationIndentWidth: 2
+Cpp11BracedListStyle: true
+DeriveLineEnding: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:
+  - foreach
+  - RTEMS_LINKER_SET_FOREACH
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks:   Preserve
+IncludeCategories:
+  - Regex:           '^(<|"(score)/)'
+    Priority:        3
+    SortPriority:    0
+  - Regex:           '^"(rtems)/'
+    Priority:        2
+    SortPriority:    0
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentCaseLabels: true
+IndentGotoLabels: true
+IndentPPDirectives: Leave
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+InsertBraces: true
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: false
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 300
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakBeforeMemberAccess: 300
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakOpenParenthesis: 0
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyIndentedWhitespace: 0
+PenaltyReturnTypeOnItsOwnLine: 500
+PointerAlignment: Right
+ReferenceAlignment: Right
+ReflowComments:  false
+SortIncludes:    false
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyBlock: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  true
+SpacesInContainerLiterals: true
+SpacesInParens: Custom
+SpacesInParensOptions:
+    ExceptDoubleParentheses: true
+    InConditionalStatements: true
+    InCStyleCasts: false
+    InEmptyParentheses: false
+    Other: true
+SpacesInSquareBrackets: true
+SpaceBeforeSquareBrackets: false
+Standard:        Latest
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
+TabWidth:        8
+UseCRLF:         false
+UseTab:          Never
+...
+