docs: Add \threadsafety to some low-hanging fruit across a few headers.

Reference Issue #7140.

include/SDL3/SDL_cpuinfo.h

@@ -60,6 +60,8 @@ extern "C" {
  *          technologies such as hyperthreading, the number of logical cores
  *          may be more than the number of physical cores.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC int SDLCALL SDL_GetNumLogicalCPUCores(void);
@@ -72,6 +74,8 @@ extern SDL_DECLSPEC int SDLCALL SDL_GetNumLogicalCPUCores(void);
  *
  * \returns the L1 cache line size of the CPU, in bytes.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC int SDLCALL SDL_GetCPUCacheLineSize(void);
@@ -84,6 +88,8 @@ extern SDL_DECLSPEC int SDLCALL SDL_GetCPUCacheLineSize(void);
  *
  * \returns true if the CPU has AltiVec features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_HasAltiVec(void);
@@ -95,6 +101,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasAltiVec(void);
  *
  * \returns true if the CPU has MMX features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_HasMMX(void);
@@ -106,6 +114,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasMMX(void);
  *
  * \returns true if the CPU has SSE features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasSSE2
@@ -122,6 +132,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasSSE(void);
  *
  * \returns true if the CPU has SSE2 features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasSSE
@@ -138,6 +150,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasSSE2(void);
  *
  * \returns true if the CPU has SSE3 features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasSSE
@@ -154,6 +168,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasSSE3(void);
  *
  * \returns true if the CPU has SSE4.1 features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasSSE
@@ -170,6 +186,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasSSE41(void);
  *
  * \returns true if the CPU has SSE4.2 features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasSSE
@@ -186,6 +204,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasSSE42(void);
  *
  * \returns true if the CPU has AVX features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasAVX2
@@ -200,6 +220,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasAVX(void);
  *
  * \returns true if the CPU has AVX2 features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasAVX
@@ -214,6 +236,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasAVX2(void);
  *
  * \returns true if the CPU has AVX-512F features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasAVX
@@ -230,6 +254,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasAVX512F(void);
  *
  * \returns true if the CPU has ARM SIMD features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_HasNEON
@@ -243,6 +269,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasARMSIMD(void);
  *
  * \returns true if the CPU has ARM NEON features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_HasNEON(void);
@@ -255,6 +283,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasNEON(void);
  *
  * \returns true if the CPU has LOONGARCH LSX features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_HasLSX(void);
@@ -267,6 +297,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasLSX(void);
  *
  * \returns true if the CPU has LOONGARCH LASX features or false if not.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC bool SDLCALL SDL_HasLASX(void);
@@ -276,6 +308,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_HasLASX(void);
  *
  * \returns the amount of RAM configured in the system in MiB.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  */
 extern SDL_DECLSPEC int SDLCALL SDL_GetSystemRAM(void);
@@ -295,6 +329,8 @@ extern SDL_DECLSPEC int SDLCALL SDL_GetSystemRAM(void);
  * \returns the alignment in bytes needed for available, known SIMD
  *          instructions.
  *
+ * \threadsafety It is safe to call this function from any thread.
+ *
  * \since This function is available since SDL 3.0.0.
  *
  * \sa SDL_aligned_alloc