SDL: Update cpuid code for clang-cl

From 6158621610a2fef5d94483352c636ad7acc50350 Mon Sep 17 00:00:00 2001
From: Nicolas Noble <[EMAIL REDACTED]>
Date: Tue, 2 Mar 2021 21:39:38 -0800
Subject: [PATCH] Update cpuid code for clang-cl

The clang-cl compiler defines `__llvm__` but not `__GNUC__`. The `__cpuid` intrinsic doesn't seem to exist with clang-cl, so the code won't link properly. The `__GNUC__` versions of these functions will work properly on Windows with clang-cl.
---
 src/cpuinfo/SDL_cpuinfo.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/cpuinfo/SDL_cpuinfo.c b/src/cpuinfo/SDL_cpuinfo.c
index 0570b4523..3117e84ae 100644
--- a/src/cpuinfo/SDL_cpuinfo.c
+++ b/src/cpuinfo/SDL_cpuinfo.c
@@ -129,7 +129,7 @@ CPU_haveCPUID(void)
 
 /* *INDENT-OFF* */
 #ifndef SDL_CPUINFO_DISABLED
-#if defined(__GNUC__) && defined(__i386__)
+#if (defined(__GNUC__) || defined(__llvm__)) && defined(__i386__)
     __asm__ (
 "        pushfl                      # Get original EFLAGS             \n"
 "        popl    %%eax                                                 \n"
@@ -147,7 +147,7 @@ CPU_haveCPUID(void)
     :
     : "%eax", "%ecx"
     );
-#elif defined(__GNUC__) && defined(__x86_64__)
+#elif (defined(__GNUC__) || defined(__llvm__)) && defined(__x86_64__)
 /* Technically, if this is being compiled under __x86_64__ then it has 
    CPUid by definition.  But it's nice to be able to prove it.  :)      */
     __asm__ (
@@ -220,7 +220,7 @@ CPU_haveCPUID(void)
     return has_CPUID;
 }
 
-#if defined(__GNUC__) && defined(__i386__)
+#if (defined(__GNUC__) || defined(__llvm__)) && defined(__i386__)
 #define cpuid(func, a, b, c, d) \
     __asm__ __volatile__ ( \
 "        pushl %%ebx        \n" \
@@ -229,7 +229,7 @@ CPU_haveCPUID(void)
 "        movl %%ebx, %%esi  \n" \
 "        popl %%ebx         \n" : \
             "=a" (a), "=S" (b), "=c" (c), "=d" (d) : "a" (func))
-#elif defined(__GNUC__) && defined(__x86_64__)
+#elif (defined(__GNUC__) || defined(__llvm__)) && defined(__x86_64__)
 #define cpuid(func, a, b, c, d) \
     __asm__ __volatile__ ( \
 "        pushq %%rbx        \n" \