Make .isa-file ##include file paths relative to including file.

Makes .isa files cleaner and simplifies scanner too.
Simplified scanner to work under both old and new versions of scons.

arch/SConscript:
    Simplify .isa scanner... seems to work with both scons 0.96.1 and 0.96.91 now.
    Assumes .isa ##include paths are relative to including file.
arch/alpha/isa/main.isa:
arch/mips/isa/formats/formats.isa:
arch/mips/isa/main.isa:
arch/sparc/isa/formats.isa:
arch/sparc/isa/main.isa:
    Make ##include paths relative to including file.
arch/isa_parser.py:
    Make ##include file paths relative to including file.
    Makes .isa files cleaner and simplifies scanner too.
    Partial rewrite of include-handling code to use cool re.sub() feature
    where you can specify a function to provide the replacement string.
    Minor cleanup of error-handling code.
    Also got rid of '#!' at top to make caller choose which python interpreter
    is used (since SPARC now requires 2.4 to build, we may need to do that via
    scons in the future).

--HG--
rename : arch/mips/isa/formats.isa => arch/mips/isa/formats/formats.isa
extra : convert_revision : 15a3920fa3aaf80cd94083eda853aa4e49425045

arch/SConscript

@@ -100,18 +100,12 @@ for hdr in isa_switch_hdrs:
 #
 import SCons.Scanner
 
-def ISAScan():
-   return SCons.Scanner.Classic("ISAScan",
-                                "$ISASUFFIXES",
-                                "SRCDIR",
-                                '^[ \t]*##[ \t]*include[ \t]*"([^>"]+)"')
+isa_scanner = SCons.Scanner.Classic("ISAScan",
+                                    [".isa", ".ISA"],
+                                    "SRCDIR",
+                                    r'^\s*##include\s+"([\w/.-]*)"')
 
-def ISAPath(env, dir, target=None, source=None, a=None):
-   return (Dir(env['SRCDIR']), Dir('.'))   
-
-iscan = Scanner(function = ISAScan().scan, skeys = [".isa", ".ISA"],
-                path_function = ISAPath)
-env.Append(SCANNERS = iscan)
+env.Append(SCANNERS = isa_scanner)
 
 #
 # Now create a Builder object that uses isa_parser.py to generate C++
@@ -138,8 +132,7 @@ def isa_desc_emitter(target, source, env):
     return (isa_desc_gen_files, [isa_parser, cpu_models_file] + source)
 
 # Pieces are in place, so create the builder.
-isa_desc_builder = Builder(action='$SOURCES $TARGET.dir $CPU_MODELS',
-                           source_scanner = iscan,
+isa_desc_builder = Builder(action='python $SOURCES $TARGET.dir $CPU_MODELS',
                            emitter = isa_desc_emitter)
 
 env.Append(BUILDERS = { 'ISADesc' : isa_desc_builder })