* libSyntax: Parse member access expression.
This patch uses createNodeInPlace from syntax parsing context API to
merge an expression with its suffix to create recursive nodes such as
member access expression.
Meanwhile, this patch breaks down a signed integer or float literal to a
prefix operator expression. This expression consists of two parts: an
operator and the following expression. This makes literals like "+1" or
"-1" no different from other prefix unary expressions such as "!true".
* Generate libSyntax API
This patch removes the hand-rolled libSyntax API and replaces it with an
API that's entirely automatically generated. This means the API is
guaranteed to be internally stylistically and functionally consistent.
Instead of spawning a thread across test iterations (whoops, out of
threads), use a thread pool of size 2. When turning off atomic caching,
this is enough to trigger a race in 5 iterations or fewer for me, so
10000 ought to be enough for most machines.
This should fix hitting the thread limit on Linux.
rdar://problem/30729901
A return statement needs something to return, so implement
integer-literal-expression too. This necessarily also forced
UnknownExprSyntax, UnknownStmtSyntax, and UnknownDeclSyntax,
which are stand-in token buckets for when we don't know
how to transform/migrate an AST.
This commit also contains the core function for caching
SyntaxData children. This is highly tricky code, with some
detailed comments in SyntaxData.{h,cpp}. The gist is that
we have to atomically swap in a SyntaxData pointer into the
child field, so we can maintain pointer identity of SyntaxData
nodes, while still being able to cache them internally.
To prove that this works, there is a multithreaded test that
checks that two threads can ask for a child that hasn't been
cached yet without crashing or violating pointer identity.
https://bugs.swift.org/browse/SR-4010
