Get alloca from stdlib.h, if possible.

* configure: try <stdlib.h> first for alloca. This should fix
a build issue which happens on the Musl library and perhaps
elsewhere. The problem on Musl is that #include <stdlib.h>
already includes <alloca.h>. That header contains an alloca
macro which interfers with our subsequent #include ALLOCA_H
directive: ALLOCA_H expands to <alloca.h> and the alloca token
gets further expanded.

1 files changed, 1 insertions, 1 deletions

diff --git a/configure b/configure
index 8cccdfc8..7e99d64d 100755
--- a/configure
+++ b/configure
@@ -2577,7 +2577,7 @@ done
 
 printf "Checking for alloca ... "
 
-for try_header in alloca.h malloc.h ; do
+for try_header in stdlib.h alloca.h malloc.h ; do
   cat > conftest.c <<!
 #include <$try_header>