[llvm] [mlir] [mlir][Python] create MLIRPythonSupport (PR #171775)

[Maksim Levental via llvm-commits]

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@@ -50,7 +54,7 @@ class PyValue;
 /// Template for a reference to a concrete type which captures a python
 /// reference to its underlying python object.
 template <typename T>
-class PyObjectRef {
+class MLIR_PYTHON_API_EXPORTED PyObjectRef {
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makslevental wrote:

These are visibility attributes right so you'll get linker errors (both on various methods and these classes' typeids themselves if they're binded via nanobind).

https://github.com/llvm/llvm-project/pull/171775