Blender Git Loki

Fix USD unit test on buildbot

The buildbot uses a separate `CMAKE_INSTALL_PREFIX`. This means that
the unit test could not find its USD JSON files in the build directory.
Using `${CMAKE_INSTALL_PREFIX}` instead of `$<TARGET_FILE_DIR:blender>`
solved this.

Partly revert "Fix T77276: Generating Python API docs raises many warnings"

This commit reverts the "noindex" part of the original commit.
using noindex made it imposible to link to a specific property.

The original warnings do not pose an issue so until a proper solution is
found I am reverting this commit.

This reverts commit 953c232db31f1a76f99ceb43119681ce0df1ab17

CTest: Fix blender_test not working on windows.

MSVC does need the wholearchive flag but it was not set,
so no tests were actually linked into the binary.

Reviewed By: sybren

Differential Revision: https://developer.blender.org/D8404

Merge branch 'blender-v2.90-release'

Fix T78308: Weight Transfer Operator "Deform Pose Bones" destination setting doesn't work.

Some modes were working by mere chance in that ugly 'reversed' case, but
the to/from selection modes were not properly swapped...

Should also be safe for 2.83.

Merge branch 'blender-v2.90-release'

Fix T78306: Weight Transfer Operator target mesh doesn't update when transforming bones.

Data transfer operator was missing tagging DEG for relations updates.

Should be portable to 2.83 as well.

Merge remote-tracking branch 'origin/blender-v2.90-release'

CMake: reject older GCC version when using precompiled Linux libraries

In the situation where the precompiled libraries are used on Linux +
GCC, a version of GCC older than 9.3 is guaranteed to cause problems.

This just implents a fatal error message when we know it doesn't make
sense to continue. We could do more checks and add some warnings, but
it's very likely that these will be ignored amongst the other noise.

Reviewed By: sergey, brecht

Differential Revision: https://developer.blender.org/D8396

Particles: support Clamp node

Cleanup: fixed compiler warning about `strncat`

`strncat(command, "x", 1)` is the same as `strcat(command, "x")`, except
that the latter form doesn't trigger a GCC warning.

No functional changes.

Cleanup: remove outdated comment

Functions: add some tests for virtual spans

Particles: initial support for events and actions

The following nodes work now (although things can still be improved of course):
Particle Birth Event, Praticle Time Step Event, Set Particle Attribute and Execute Condition.

Multiple Set Particle Attribute nodes can be chained using the "Execute" sockets.
They will be executed from left to right.

Merge branch 'blender-v2.90-release'

Cycles: Enable OptiX on first generation Maxwell GPUs again

Merge remote-tracking branch 'origin/blender-v2.90-release'

Cleanup: Fix compiler warning about function without prototype

No functional changes.

Merge remote-tracking branch 'origin/blender-v2.90-release'

Cleanup: Fix compiler warning about missing parentheses

The code was well-defined, given that `&&` binds stronger than `||`, but
still GCC warns about this.

No functional changes.