BaseTools: Update Build tool to support multiple workspaces

WORKSPACE is still kept.
New PACKAGES_PATH is introduced to specify the additional WORKSPACEs.
In PACKAGES_PATH, ';' is separator in Windows, ':' is separator in Linux.

Build directory is in WORKSPACE. Package, BaseTools and Conf directory
will be found from WORKSPACE and PACKAGES_PATH.

In implementation, BaseTools adds MultipleWorkspace class for
the file path conversion from WORKSPACE and PACKAGES_PATH.

Verify two tree layouts.
Root\edk2\MdePkg
Root\edk2\MdeMdeModulePkg
Root\edk2\...
1. set WORKSPACE=Root\edk2
2. set WORKSPACE=Root, and set PACKAGES_PATH=Root\edk2

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Li YangX <yangx.li@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18579 6f19259b-4bc3-4df7-8a09-765794883524

BaseTools/Source/Python/GenFds/GenFdsGlobalVariable.py

@@ -31,6 +31,7 @@ from AutoGen.BuildEngine import BuildRule
 import Common.DataType as DataType
 from Common.Misc import PathClass
 from Common.LongFilePathSupport import OpenLongFilePath as open
+from Common.MultipleWorkspace import MultipleWorkspace as mws
 
 ## Global variables
 #
@@ -322,12 +323,13 @@ class GenFdsGlobalVariable:
     #   @param  String           String that may contain macro
     #
     def ReplaceWorkspaceMacro(String):
+        String = mws.handleWsMacro(String)
         Str = String.replace('$(WORKSPACE)', GenFdsGlobalVariable.WorkSpaceDir)
         if os.path.exists(Str):
             if not os.path.isabs(Str):
                 Str = os.path.abspath(Str)
         else:
-            Str = os.path.join(GenFdsGlobalVariable.WorkSpaceDir, String)
+            Str = mws.join(GenFdsGlobalVariable.WorkSpaceDir, String)
         return os.path.normpath(Str)
 
     ## Check if the input files are newer than output files