[glibc/maskray/unnest] configure: Fix check for INSERT in linker script

[glibc/maskray/unnest] configure: Fix check for INSERT in linker script

[Fangrui Song]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=5f07d47e4b3d137edfbe3ea6c4eeba1ea6cfa54d

commit 5f07d47e4b3d137edfbe3ea6c4eeba1ea6cfa54d
Author: Fangrui Song <maskray@google.com>
Date:   Mon Sep 13 12:39:20 2021 -0700

    configure: Fix check for INSERT in linker script
    
    GCC/Clang use local access when referencing a const variable,
    so the conftest.so may have no dynamic relocation.
    LLD reports `error: unable to insert .foo after .rela.dyn` when the
    destination section does not exist.
    
    Use a non-const int to ensure that .rela.dyn exists.
    
    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

Diff:
---
 configure    | 2 +-
 configure.ac | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 542802ad35..39d75eb4ed 100755
--- a/configure
+++ b/configure
@@ -5793,7 +5793,7 @@ if ${libc_cv_insert+:} false; then :
   $as_echo_n "(cached) " >&6
 else
   cat > conftest.c <<EOF
-		const int __attribute__ ((section(".bar"))) bar = 0x12345678;
+		int __attribute__ ((section(".bar"))) bar = 0x12345678;
 		int test (void) { return bar; }
 EOF
 		cat > conftest.t <<EOF
diff --git a/configure.ac b/configure.ac
index d9232418de..00f49f09f7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1217,7 +1217,7 @@ AC_SUBST(libc_cv_protected_data)
 AC_CACHE_CHECK(linker support for INSERT in linker script,
 	       libc_cv_insert,
 	       [cat > conftest.c <<EOF
-		const int __attribute__ ((section(".bar"))) bar = 0x12345678;
+		int __attribute__ ((section(".bar"))) bar = 0x12345678;
 		int test (void) { return bar; }
 EOF
 		cat > conftest.t <<EOF