clang-format: Add options for SpacesInParentheses

[Hedede]

I am working on a project where function declarations and functions calls are formatted differently:
void foo( Arg x, Arg y ); // decl
foo(a, b) // call

From what I could gather, SpacesInParentheses doens't support differentiation. There are SpacesInCStyleCastParentheses, SpacesInConditionalStatement, but that' snot enough.

I suggest to add something analogous to BraceWrapping

• FunctionDecl (maybe also MemberFunctionDecl? I don't think it's needed though) void foo(A a)
• FunctionCall foo(x)
• FunctionLikeMacroDecl #define FOO( x )
• FunctionLikeMacroCall FOO(x)
• TemplateDecl template<typename T>
• TemplateInstantiation Foo<T>
• ConditionalStatement
• Operator (sizeof, alignof...)
• Decltype
• Expression ( a + b )
• CStyleCast
• Braced initializer list
• ... Maybe more?

[llvmbot]

@llvm/issue-subscribers-clang-format

[gedare]

I have submitted https://reviews.llvm.org/D155239 to enable the possibility to add these finer-grained controls of space insertion.

[gedare]

I have submitted https://reviews.llvm.org/D156360 to add the requested control over spaces inside of function calls vs function declarations.