Clang-format tweaks (#15906)

.clang-format

@@ -5,6 +5,9 @@ AlignConsecutiveAssignments: 'true'
 AlignConsecutiveDeclarations: 'true'
 AlignOperands: 'true'
 AllowAllParametersOfDeclarationOnNextLine: 'false'
+AllowShortCaseLabelsOnASingleLine: 'false'
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortLoopsOnASingleLine: 'false'
 AlwaysBreakAfterDefinitionReturnType: None
 AlwaysBreakAfterReturnType: None
 AlwaysBreakBeforeMultilineStrings: 'false'
@@ -20,6 +23,7 @@ SortIncludes: 'false'
 SpaceBeforeAssignmentOperators: 'true'
 SpaceBeforeParens: ControlStatements
 SpaceInEmptyParentheses: 'false'
+SpacesBeforeTrailingComments: 1
 TabWidth: '4'
 UseTab: Never