Use __NEWLIB__ instead of __SWITCH__ and __CYGWIN__ for alloca.h-detection (#3070)
Cygwin uses newlib, so it's covered by the __NEWLIB__ check.
You can see how it defines __NEWLIB__ here: https://cygwin.com/git/?p=newlib-cygwin.git;a=blob;f=newlib/configure.in#l453
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 954c553..1df83d1 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -36,7 +36,7 @@
#include <stdio.h> // vsnprintf, sscanf, printf
#if !defined(alloca)
-#if defined(__GLIBC__) || defined(__sun) || defined(__CYGWIN__) || defined(__APPLE__) || defined(__SWITCH__)
+#if defined(__GLIBC__) || defined(__sun) || defined(__APPLE__) || defined(__NEWLIB__)
#include <alloca.h> // alloca (glibc uses <alloca.h>. Note that Cygwin may have _WIN32 defined, so the order matters here)
#elif defined(_WIN32)
#include <malloc.h> // alloca
