Fix T71461: Add IN_PLACE_INSTANCES to `part_prim` and `part_axis` object mode particle shaders

For `Particle Properties -> Viewport Display -> Display As` set to
circle/cross/axis, particle instances are associated with a single
resource handle (and, in particular, a single model matrix), so define
`IN_PLACE_INSTANCES` to get the right index for `ModelMatrix` and
`ModelInverseMatrix` in the shader.

Differential Revision: https://developer.blender.org/D6220

Revert wrong merge from origin/master

Fix T71461: Add IN_PLACE_INSTANCES to `part_prim` and `part_axis` object mode particle shaders

For `Particle Properties -> Viewport Display -> Display As` set to
circle/cross/axis, particle instances are associated with a single
resource handle (and, in particular, a single model matrix), so define
`IN_PLACE_INSTANCES` to get the right index for `ModelMatrix` and
`ModelInverseMatrix` in the shader.

Differential Revision: https://developer.blender.org/D6220

Fluid Particles: fix threading crash with viscoelastic springs.

As correctly pointed out by a comment in the code, adding
new springs wasn't thread safe, and caused crashes.

Fix by buffering new springs in intermediate thread-local
arrays, which are flushed on the main thread. This is valid
because the new springs are not used until the next sim step.

Differential Revision: https://developer.blender.org/D6133

make_update.py: update windows library folder

Fix T71436: proportional_edit_objects turns off when translating cursor in edit mode

Windows: Fix build errors during deps build on windows.

Fix T69799: Glitches when moving object camera is locked to

The idea is to indicate that the view3d matrix is being transformed too
and this avoids cyclic dependencies.

UI: Graph Editor Insert Keyframes Menu

Fixes alignment issues on Graph Editor menus used to insert keyframes.

Differential Revision: https://developer.blender.org/D6213

Reviewed by Campbell Barton

Cleanup: adjust layout for example experimental UI

- Use a separate split for each feature,
since two top-level splits can become un-aligned.
- Only show the task instead of the entire URL.

Windows: Switch to the dynamic C runtime

This change switches windows to the dynamic C runtime
avoiding issues coming from mixing the static and dynamic
runtime like the ones outlined in [1]

[1] https://developer.blender.org/D5387#122165

Differential Revision: https://developer.blender.org/D6175

Reviewed by: @Sergey

User Preference Experimental Tab

Experimental tab in User Preferences for experimental features.
The tab option is only visible when "Developer Extras" is on.

Included here is a (commented out) example panel to be used as a
template for the new experimental panels. Since these panels will come
and go it is nice to have a reference in the code.

Differential Revision: https://developer.blender.org/D6203

Fix tool leader-key consuming mouse wheel events

Stretch To: clean up the math code in the implementation.

Combine computing `size` and normalizing the matrix, invert the
direction of `vec` to avoid negating it later, use `rescale_m4`
instead of matrix multiplication to scale the final result.

Differential Revision: https://developer.blender.org/D6134

Cleanup: clang-format

Fix broken selection behavior in multiple editors right after saving

Steps to recreate were:
* Open a Node Editor, add some nodes
* Save the file
* Select all nodes (A)
* Save it again, but with Ctrl+S
* Try to select an already selected node
It's supposed to deselect other nodes now, but for as long as the report
banner is shown in the status-bar ('Saved "foo.blend"'), this doesn't
work.

Also happened in the VSE, Dopesheet, NLA or everywhere else we recently
added drag-all-selected support to.

Issue was in there since 2.80. Basically the timer event sent by the
report banner broke assumptions in the selection operator.

Hope this fix doesn't have any side effects. Checked with Bastien
(initial author of this logic), but seems things are fine.

Stretch To: implement a mode similar to Damped Track for rotation.

Most of the time Stretch To is used in actual rigs, like BlenRig
or Rigify, in combination with Damped Track to handle rotation
before the stretch, because it produces rotations more appropriate
for organic deformation, and doesn't flip because of internal
gimbal lock.

The prevalence of this pattern suggests that Stretch To should
support that kind of rotation directly as an option.

Differential Revision: https://developer.blender.org/D6134

Fix crash when adding Scene variable to a driver

When a Scene variable is added to a driver, and the RNA path is still NULL,
it no longer crashes Blender.

Constraints: remove special meaning of Local Space for parentless Objects.

In 2011 special handling was introduced, apparently for no other
reason than to address a complaint in T25707 that World and Local
space are equivalent for objects without parent. This causes issues
and confusion, as mentioned in rB599c8a2c8e4.

This special meaning of Local Space is not documented in the manual,
and is not known to experienced riggers, so removing it should not
be a problem.

Differential Revision: https://developer.blender.org/D6095

Fix T71336: GPencil: Wrong mouse cursor