[gnome-builder] build: explicitly test for pcre.h

[Christian Hergert <chergert src gnome org>]

commit 1a36b2d95c94afba87808f511a59d761cbc9aa0b
Author: Christian Hergert <christian hergert me>
Date:   Mon Aug 31 02:19:37 2015 -0700

    build: explicitly test for pcre.h
    
    This is needed by editorconfig glob matching.

 configure.ac |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index b587d18..0594552 100644
--- a/configure.ac
+++ b/configure.ac
@@ -73,6 +73,12 @@ PKG_PROG_PKG_CONFIG([0.22])
 
 
 dnl ***********************************************************************
+dnl Check for Required Headers
+dnl ***********************************************************************
+AC_CHECK_HEADER([pcre.h])
+
+
+dnl ***********************************************************************
 dnl Ensure C11 is Supported
 dnl ***********************************************************************
 AX_CHECK_COMPILE_FLAG([-std=gnu11],