Move to /usr prefix.

- This is much more standard and replaces /image in sysa and is the
  standard in sysc (avoids many issues).
- GCC needs to have a file created for some unknown reason.
- Checksums updated.

sysa/gcc-4.7.4/patches/remove_gperf_dependency.patch

@@ -1,36 +0,0 @@
-SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
-SPDX-License-Identifier: GPL-3.0-or-later
-
-Remove dependency on gperf.
-
---- gcc/cp/except.c	2021-07-07 18:24:36.561530121 +0100
-+++ gcc/cp/except.c	2021-07-07 18:27:18.035681929 +0100
-@@ -987,8 +987,6 @@
-    exception, unless it calls a program-supplied function that
-    throws an exception.  */
- 
--#include "cfns.h"
--
- int
- nothrow_libfn_p (const_tree fn)
- {
-@@ -1007,7 +1005,7 @@
-      unless the system headers are playing rename tricks, and if
-      they are, we don't want to be confused by them.  */
-   id = DECL_NAME (fn);
--  return !!libc_name_p (IDENTIFIER_POINTER (id), IDENTIFIER_LENGTH (id));
-+  return 0;
- }
- 
- /* Returns nonzero if an exception of type FROM will be caught by a
---- gcc/cp/Make-lang.in	2021-07-07 18:24:36.571530380 +0100
-+++ gcc/cp/Make-lang.in	2021-07-07 18:26:47.154887799 +0100
-@@ -313,7 +313,7 @@
- cp/rtti.o: cp/rtti.c $(CXX_TREE_H) $(TM_H) $(FLAGS_H) convert.h \
-   $(TARGET_H) $(C_PRAGMA_H) gt-cp-rtti.h intl.h
- cp/except.o: cp/except.c $(CXX_TREE_H) $(TM_H) $(FLAGS_H) \
--  cp/cfns.h $(TREE_INLINE_H) $(TARGET_H) gt-cp-except.h
-+  $(TREE_INLINE_H) $(TARGET_H) gt-cp-except.h
- cp/expr.o: cp/expr.c $(CXX_TREE_H) $(TM_H) $(FLAGS_H) $(TM_P_H)
- cp/pt.o: cp/pt.c $(CXX_TREE_H) $(TM_H) cp/decl.h cp/cp-objcp-common.h \
-   toplev.h $(TREE_INLINE_H) pointer-set.h gt-cp-pt.h vecprim.h intl.h \