From: Jonathan Kew <jkew@mozilla.com>
Subject: Adjust pixman-arm-asm for Mozilla-specific build needs

diff --git a/gfx/cairo/libpixman/src/pixman-arm-asm.h b/gfx/cairo/libpixman/src/pixman-arm-asm.h
--- a/gfx/cairo/libpixman/src/pixman-arm-asm.h
+++ b/gfx/cairo/libpixman/src/pixman-arm-asm.h
@@ -23,17 +23,19 @@
  *
  * Author:  Jeff Muizelaar (jeff@infidigm.net)
  *
  */
 
 #ifndef PIXMAN_ARM_ASM_H
 #define PIXMAN_ARM_ASM_H
 
+#ifdef HAVE_CONFIG_H
 #include "pixman-config.h"
+#endif
 
 /*
  * References:
  *  - https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros
  *  - https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst
  */
 #if defined(__ARM_FEATURE_BTI_DEFAULT) && __ARM_FEATURE_BTI_DEFAULT == 1
   #define BTI_C hint 34  /* bti c: for calls, IE bl instructions */