Search path environment variables for cross-compilers.  See the discussion
at <http://gcc.gnu.org/ml/gcc/2013-02/msg00124.html>.

Note: Touch 'C_INCLUDE_PATH' et al. rather than 'CPATH', as discussed
at <http://bugs.gnu.org/22186>.

diff --git a/gcc/gcc.c b/gcc/gcc.c
index eced0d5..08dec2b 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -4317,7 +4317,7 @@ process_command (unsigned int decoded_options_count,
     }
 
   temp = env.get (LIBRARY_PATH_ENV);
-  if (temp && *cross_compile == '0')
+  if (temp)
     {
       const char *startp, *endp;
       char *nstore = (char *) alloca (strlen (temp) + 3);
diff --git a/gcc/incpath.c b/gcc/incpath.c
index 98fe5ec..96aff65 100644
--- a/gcc/incpath.c
+++ b/gcc/incpath.c
@@ -461,8 +461,8 @@ register_include_chains (cpp_reader *pfile, const char *sysroot,
 			 int stdinc, int cxx_stdinc, int verbose)
 {
   static const char *const lang_env_vars[] =
-    { "C_INCLUDE_PATH", "CPLUS_INCLUDE_PATH",
-      "OBJC_INCLUDE_PATH", "OBJCPLUS_INCLUDE_PATH" };
+    { "CROSS_C_INCLUDE_PATH", "CROSS_CPLUS_INCLUDE_PATH",
+      "CROSS_OBJC_INCLUDE_PATH", "CROSS_OBJCPLUS_INCLUDE_PATH" };
   cpp_options *cpp_opts = cpp_get_options (pfile);
   size_t idx = (cpp_opts->objc ? 2: 0);
 
@@ -473,7 +473,7 @@ register_include_chains (cpp_reader *pfile, const char *sysroot,
 
   /* CPATH and language-dependent environment variables may add to the
      include chain.  */
-  add_env_var_paths ("CPATH", BRACKET);
+  add_env_var_paths ("CROSS_CPATH", BRACKET);
   add_env_var_paths (lang_env_vars[idx], SYSTEM);
 
   target_c_incpath.extra_pre_includes (sysroot, iprefix, stdinc);
diff --git a/gcc/system.h b/gcc/system.h
index 0cbf60a..3242c68 100644
--- a/gcc/system.h
+++ b/gcc/system.h
@@ -1169,4 +1169,6 @@ helper_const_non_const_cast (const char *p)
 /* Get definitions of HOST_WIDE_INT.  */
 #include "hwint.h"
 
+#define LIBRARY_PATH_ENV "CROSS_LIBRARY_PATH"
+
 #endif /* ! GCC_SYSTEM_H */
diff --git a/gcc/tlink.c b/gcc/tlink.c
index a2a7db0..2d96872 100644
--- a/gcc/tlink.c
+++ b/gcc/tlink.c
@@ -456,7 +456,7 @@ recompile_files (void)
   file *f;
 
   putenv (xstrdup ("COMPILER_PATH="));
-  putenv (xstrdup ("LIBRARY_PATH="));
+  putenv (xstrdup (LIBRARY_PATH_ENV "="));
 
   while ((f = file_pop ()) != NULL)
     {
f='/guix/log/gnu/packages/image.scm?id=fb2347f6d161db0c0ec5fd8fd952ab8cdb7c2738'>image.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/image.scm?id=fb2347f6d161db0c0ec5fd8fd952ab8cdb7c2738&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-07-18 10:45:29 +0800'>2024-07-18</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=e9b97b193a9b444399b3cdb33e10906087664b39'>gnu: freeimage: Adjust for libraw 0.21.</a><span class='msg-avail'>...</span></td><td>Zheng Junjie</td></tr>
<tr><td><span title='2024-07-18 10:44:58 +0800'>2024-07-18</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=bd3ad17ded13174345a12c2d11dc28eddda82e93'>gnu: libavif: Update to 1.0.4.</a><span class='msg-avail'>...</span></td><td>Zheng Junjie</td></tr>
<tr><td><span title='2024-07-01 13:54:59 -0500'>2024-07-01</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=85012e64819b39fd6112038134548b415fd5daff'>gnu: mini: Update to 0.9.15.</a><span class='msg-avail'>...</span></td><td>Artyom V. Poptsov</td></tr>
<tr><td><span title='2024-04-06 08:00:59 -0300'>2024-04-06</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=38e93600b5cb62fd40d1c1b36ae7ca5c20718746'>gnu: libheif: Enable tests.</a><span class='msg-avail'>...</span></td><td>Vinicius Monego</td></tr>
<tr><td><span title='2024-04-06 08:00:59 -0300'>2024-04-06</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=84d21fdbaf833b1fdf066cd00cd7464c49a2c658'>gnu: libheif: Update to 1.17.6.</a><span class='msg-avail'>...</span></td><td>Vinicius Monego</td></tr>
<tr><td><span title='2024-04-02 16:19:16 +0300'>2024-04-02</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=9142c50c6db0e84b165d732b60693edf8fae500e'>gnu: libjxl: Fix build on riscv64-linux.</a><span class='msg-avail'>...</span></td><td>Zheng Junjie</td></tr>
<tr><td><span title='2024-02-24 11:14:46 +0100'>2024-02-24</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=ad08af2fea53f728ec001b9dfcd36fecb73c848e'>gnu: leptonica: Update to 1.84.1.</a><span class='msg-avail'>...</span></td><td>Ahmad Draidi</td></tr>
<tr><td><span title='2024-02-24 10:59:22 +0100'>2024-02-24</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=df5653adcbd1f9799f810f46d514b2ca4112af97'>gnu: leptonica: Fix random test failures.</a><span class='msg-avail'>...</span></td><td>Ahmad Draidi</td></tr>
<tr><td><span title='2024-02-22 16:12:22 +0100'>2024-02-22</span></td><td><a href='/guix/commit/gnu/packages/image.scm?id=8f250436172c8d028a1d62ff8b9b5daae73e4f3a'>gnu: Add libsixel.</a><span class='msg-avail'>...</span></td><td>chris</td></tr>