Add support for startup data (snapshot) compression.

SConstruct

Index: SConstruct
diff --git a/SConstruct b/SConstruct
index 82b83ceafa0c0dfd87dff352b5cda7ea63151dbc..ed9ddd4b11c450f89b9d3fafb18c8508cb3e839b 100644
--- a/SConstruct
+++ b/SConstruct
@@ -201,6 +201,9 @@ LIBRARY_FLAGS = {
     },
     'gdbjit:on': {
       'CPPDEFINES':   ['ENABLE_GDB_JIT_INTERFACE']
+    },
+    'compress_startup_data:bz2': {
+      'CPPDEFINES':   ['COMPRESS_STARTUP_DATA_BZ2']
     }
   },
   'msvc': {
@@ -338,6 +341,9 @@ MKSNAPSHOT_EXTRA_FLAGS = {
     'os:win32': {
       'LIBS': ['winmm', 'ws2_32'],
     },

[Søren Thygesen Gjesse, 2011/04/29 06:50:29]

As this is Linux only I think this should be either inside the os:linux section
above or have a 'os:linux' inside. I think an os:linux here is the best choice,
and makes adding more platforms most logical.

[mnaganov (inactive), 2011/04/29 12:07:58]

Done.

+    'compress_startup_data:bz2': {
+      'LIBS': ['bz2']
+    },
   },
   'msvc': {
     'all': {
@@ -478,6 +484,10 @@ SAMPLE_FLAGS = {
       'CCFLAGS':      ['-g', '-O0'],
       'CPPDEFINES':   ['DEBUG']
     },
+    'compress_startup_data:bz2': {
+      'CPPDEFINES':   ['COMPRESS_STARTUP_DATA_BZ2'],

[Søren Thygesen Gjesse, 2011/04/29 06:50:29]

Ditto for the LIBS part.

[mnaganov (inactive), 2011/04/29 12:07:58]

Done.

+      'LIBS':         ['bz2']
+    },
   },
   'msvc': {
     'all': {
@@ -919,7 +929,12 @@ SIMPLE_OPTIONS = {
     'values': ['mips32r2', 'mips32r1'],
     'default': 'mips32r2',
     'help': 'mips variant'
-  }
+  },
+  'compress_startup_data': {
+    'values': ['off', 'bz2'],
+    'default': 'off',
+    'help': 'compress startup data (snapshot) [Linux only]'
+  },
 }
 
 ALL_OPTIONS = dict(PLATFORM_OPTIONS, **SIMPLE_OPTIONS)
@@ -1042,6 +1057,8 @@ def VerifyOptions(env):
     print env['arch']
     print env['simulator']
     Abort("Option unalignedaccesses only supported for the ARM architecture.")
+  if env['os'] != 'linux' and env['compress_startup_data'] != 'off':
+    Abort("Startup data compression is only available on Linux")
   for (name, option) in ALL_OPTIONS.iteritems():
     if (not name in env):
       message = ("A value for option %s must be specified (%s)." %