Copy changes from the no-history fork, generated back in 2023

Original commit message:
> commit f138311d2d2e0cc9ba0496d523bb46f2c1c9fb73
> Author: rtk0c <[email protected]>
> Date:   Wed Sep 20 23:58:58 2023 -0700
>
>     Copy from the PlasticSCM repo, replace vendored glm wtih conan

In reality, this also introduced a few uncommitted changes in the
original PlasticSCM repo. See the modified and new files in this patch.

1 files changed, 0 insertions, 153 deletions

diff --git a/3rdparty/glfw/source/tests/threads.c b/3rdparty/glfw/source/tests/threads.c
deleted file mode 100644
index ec13b00..0000000
--- a/3rdparty/glfw/source/tests/threads.c
+++ /dev/null
@@ -1,153 +0,0 @@
-//========================================================================
-// Multi-threading test
-// Copyright (c) Camilla Löwy <[email protected]>
-//
-// This software is provided 'as-is', without any express or implied
-// warranty. In no event will the authors be held liable for any damages
-// arising from the use of this software.
-//
-// Permission is granted to anyone to use this software for any purpose,
-// including commercial applications, and to alter it and redistribute it
-// freely, subject to the following restrictions:
-//
-// 1. The origin of this software must not be misrepresented; you must not
-//    claim that you wrote the original software. If you use this software
-//    in a product, an acknowledgment in the product documentation would
-//    be appreciated but is not required.
-//
-// 2. Altered source versions must be plainly marked as such, and must not
-//    be misrepresented as being the original software.
-//
-// 3. This notice may not be removed or altered from any source
-//    distribution.
-//
-//========================================================================
-//
-// This test is intended to verify whether the OpenGL context part of
-// the GLFW API is able to be used from multiple threads
-//
-//========================================================================
-
-#include "tinycthread.h"
-
-#define GLAD_GL_IMPLEMENTATION
-#include <glad/gl.h>
-#define GLFW_INCLUDE_NONE
-#include <GLFW/glfw3.h>
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <math.h>
-
-typedef struct
-{
-    GLFWwindow* window;
-    const char* title;
-    float r, g, b;
-    thrd_t id;
-} Thread;
-
-static volatile int running = GLFW_TRUE;
-
-static void error_callback(int error, const char* description)
-{
-    fprintf(stderr, "Error: %s\n", description);
-}
-
-static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
-{
-    if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
-        glfwSetWindowShouldClose(window, GLFW_TRUE);
-}
-
-static int thread_main(void* data)
-{
-    const Thread* thread = data;
-
-    glfwMakeContextCurrent(thread->window);
-    glfwSwapInterval(1);
-
-    while (running)
-    {
-        const float v = (float) fabs(sin(glfwGetTime() * 2.f));
-        glClearColor(thread->r * v, thread->g * v, thread->b * v, 0.f);
-
-        glClear(GL_COLOR_BUFFER_BIT);
-        glfwSwapBuffers(thread->window);
-    }
-
-    glfwMakeContextCurrent(NULL);
-    return 0;
-}
-
-int main(void)
-{
-    int i, result;
-    Thread threads[] =
-    {
-        { NULL, "Red", 1.f, 0.f, 0.f, 0 },
-        { NULL, "Green", 0.f, 1.f, 0.f, 0 },
-        { NULL, "Blue", 0.f, 0.f, 1.f, 0 }
-    };
-    const int count = sizeof(threads) / sizeof(Thread);
-
-    glfwSetErrorCallback(error_callback);
-
-    if (!glfwInit())
-        exit(EXIT_FAILURE);
-
-    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
-
-    for (i = 0;  i < count;  i++)
-    {
-        threads[i].window = glfwCreateWindow(200, 200,
-                                             threads[i].title,
-                                             NULL, NULL);
-        if (!threads[i].window)
-        {
-            glfwTerminate();
-            exit(EXIT_FAILURE);
-        }
-
-        glfwSetKeyCallback(threads[i].window, key_callback);
-
-        glfwSetWindowPos(threads[i].window, 200 + 250 * i, 200);
-        glfwShowWindow(threads[i].window);
-    }
-
-    glfwMakeContextCurrent(threads[0].window);
-    gladLoadGL(glfwGetProcAddress);
-    glfwMakeContextCurrent(NULL);
-
-    for (i = 0;  i < count;  i++)
-    {
-        if (thrd_create(&threads[i].id, thread_main, threads + i) !=
-            thrd_success)
-        {
-            fprintf(stderr, "Failed to create secondary thread\n");
-
-            glfwTerminate();
-            exit(EXIT_FAILURE);
-        }
-    }
-
-    while (running)
-    {
-        glfwWaitEvents();
-
-        for (i = 0;  i < count;  i++)
-        {
-            if (glfwWindowShouldClose(threads[i].window))
-                running = GLFW_FALSE;
-        }
-    }
-
-    for (i = 0;  i < count;  i++)
-        glfwHideWindow(threads[i].window);
-
-    for (i = 0;  i < count;  i++)
-        thrd_join(threads[i].id, &result);
-
-    exit(EXIT_SUCCESS);
-}
-