From: Jan Engelhardt <jengelh@inai.de>
Date: 2017-02-02 19:42:44.679588946 +0100

build: workaround gcc 4.8 bug

tools/io.h:41:38:
error: ignoring return value of 'long int ftell(FILE*)',
declared with attribute warn_unused_result [-Werror=unused-result,-Werror]
       if (sizeof(T) != 1 && (ftell(fp) % sizeof(T))) {

Workaround gcc 4.8's wrongful idea that ftell's return value
were ignored.
---
 tools/io.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: SPIRV-Tools-2021.1/tools/io.h
===================================================================
--- SPIRV-Tools-2021.1.orig/tools/io.h
+++ SPIRV-Tools-2021.1/tools/io.h
@@ -60,7 +60,8 @@ bool WasFileCorrectlyRead(FILE* file, co
       return false;
     }
   } else {
-    if (sizeof(T) != 1 && (ftell(file) % sizeof(T))) {
+    long ftx = ftell(file);
+    if (sizeof(T) != 1 && ftx % sizeof(T) != 0) {
       fprintf(
           stderr,
           "error: file size should be a multiple of %zd; file '%s' corrupt\n",