Start using Github Actions (#1488)

* Start using Github Actions

Build on windows and linux. Cannot build for macos,
since the builders only support xcode 10+ which dropped
x86 support.

* Build sourcepawn tooling as separate package

Upload build artifacts containing only spcomp and the includes.
This adds a new `--scripting-only` flag to configure.py which skips
everything and goes straight to building spcomp and packaging the
include folder with it.

* Only run the workflows for the master branch

* Split common operations into PackageHelpers file

Don't duplicate the code for packaging releases for the tooling-only packages. Instead use a common `PackageHelpers` class which provides the functionality common to both packages.

This replaces the explicit list of files to package with a directory scan, so we don't have to list them all.

The pgsql sql-init-scripts were missing from the release package before, so they were added here as well. Three scripts from the testsuite were missing from the explicit list (mapdisplayname, floats, findmap), so they're now included.

* Fix Python 2 compatibility

os.scandir is Python 3 only.

AMBuildScript

@@ -331,7 +331,7 @@ class SMConfig(object):
       cxx.cflags += ['-Wno-sometimes-uninitialized']
 
     # Work around SDK warnings.
-    if cxx.version >= 'clang-10.0':
+    if cxx.version >= 'clang-10.0' or cxx.version >= 'apple-clang-12.0':
         cxx.cflags += [
             '-Wno-implicit-int-float-conversion',
             '-Wno-tautological-overlap-compare',
@@ -667,7 +667,8 @@ if getattr(builder, 'target', None) is not None:
 
 SM = SMConfig()
 SM.detectProductVersion()
-SM.detectSDKs()
+if not getattr(builder.options, 'scripting_only', False):
+  SM.detectSDKs()
 SM.configure()
 SM.add_libamtl()
 
@@ -703,47 +704,60 @@ class SPRoot(object):
   def libamtl(self):
     return SM.libamtl
 
+SP_build_parts = ['core']
+if getattr(builder.options, 'scripting_only', False):
+  SP_build_parts = ['spcomp']
+
 # Build SourcePawn externally.
 SP = builder.Build('sourcepawn/AMBuildScript', {
   'external_root': SPRoot(),
   'external_amtl': os.path.join(builder.sourcePath, 'public', 'amtl'),
-  'external_build': ['core'],
+  'external_build': SP_build_parts,
 })
 if len(SP.spcomp) > 1:
   SM.spcomp = SP.spcomp['x86']
 else:
   SM.spcomp = SP.spcomp[list(SP.spcomp.keys())[0]]
 SM.spcomp_bins = list(SP.spcomp.values())
-for cxx in SM.all_targets:
-  SM.spvm += [
-     SP.libsourcepawn[cxx.target.arch]
+
+if not getattr(builder.options, 'scripting_only', False):
+  for cxx in SM.all_targets:
+    SM.spvm += [
+      SP.libsourcepawn[cxx.target.arch]
+    ]
+
+if getattr(builder.options, 'scripting_only', False):
+  BuildScripts = [
+    'tools/buildbot/PackageHelpers',
+    'tools/buildbot/ToolsPackageScript',
+  ]
+else:
+  BuildScripts = [
+    'loader/AMBuilder',
+    'core/AMBuilder',
+    'core/logic/AMBuilder',
+    'extensions/bintools/AMBuilder',
+    'extensions/clientprefs/AMBuilder',
+    'extensions/curl/AMBuilder',
+    'extensions/cstrike/AMBuilder',
+    'extensions/geoip/AMBuilder',
+    'extensions/mysql/AMBuilder',
+    'extensions/pgsql/AMBuilder',
+    'extensions/regex/AMBuilder',
+    'extensions/sdkhooks/AMBuilder',
+    'extensions/sdktools/AMBuilder',
+    'extensions/sqlite/AMBuilder',
+    'extensions/tf2/AMBuilder',
+    'extensions/topmenus/AMBuilder',
+    'extensions/updater/AMBuilder',
   ]
 
-BuildScripts = [
-  'loader/AMBuilder',
-  'core/AMBuilder',
-  'core/logic/AMBuilder',
-  'extensions/bintools/AMBuilder',
-  'extensions/clientprefs/AMBuilder',
-  'extensions/curl/AMBuilder',
-  'extensions/cstrike/AMBuilder',
-  'extensions/geoip/AMBuilder',
-  'extensions/mysql/AMBuilder',
-  'extensions/pgsql/AMBuilder',
-  'extensions/regex/AMBuilder',
-  'extensions/sdkhooks/AMBuilder',
-  'extensions/sdktools/AMBuilder',
-  'extensions/sqlite/AMBuilder',
-  'extensions/tf2/AMBuilder',
-  'extensions/topmenus/AMBuilder',
-  'extensions/updater/AMBuilder',
-]
-
-if builder.backend == 'amb2':
-  BuildScripts += [
-    'plugins/AMBuilder',
-    'tools/buildbot/PackageScript',
-  ]
+  if builder.backend == 'amb2':
+    BuildScripts += [
+      'plugins/AMBuilder',
+      'tools/buildbot/PackageHelpers',
+      'tools/buildbot/PackageScript',
+    ]
 
 builder.Build(BuildScripts, { 'SM': SM })