UefiPayloadPkg: Add new option "--add_cc_flags" in UniversalPayloadBuild.py

Add new option "--add_cc_flag" to append CC compilation flags when build
Payload. With this option, user can append specified build options in
build script.

Usage example to add more CC flags:
python UefiPayloadPkg/UniversalPayloadBuild.py -t GCC5 -b DEBUG --Fit \
    --add_cc_flag=-mno-sse --add_cc_flag=-mno-mmx

Signed-off-by: Ajan Zhong <ajan.zhong@newfw.com>

UefiPayloadPkg/UefiPayloadPkg.dsc

@@ -175,6 +175,7 @@
   INTEL:RELEASE_*_*_CC_FLAGS     = /D MDEPKG_NDEBUG
   MSFT:RELEASE_*_*_CC_FLAGS      = /D MDEPKG_NDEBUG
 !endif
+  *_*_*_CC_FLAGS                 = $(APPEND_CC_FLAGS)
 
 [BuildOptions.AARCH64]
   GCC:*_*_*_CC_FLAGS         = -mcmodel=tiny -mstrict-align

UefiPayloadPkg/UniversalPayloadBuild.py

@@ -164,6 +164,14 @@ def BuildUniversalPayload(Args):
         for MacroItem in Args.Macro:
             Defines += " -D {}".format (MacroItem)
 
+    if (Args.add_cc_flags!= None):
+        CcFlags = " ".join(Args.add_cc_flags)
+
+        # Wrap the CC flags with double quotes since we might have plenty of
+        # specified build options
+        FinalFlags = f'"{CcFlags}"'
+        Defines += " -D APPEND_CC_FLAGS={}".format (FinalFlags)
+
     #
     # Building DXE core and DXE drivers as DXEFV.
     #
@@ -330,6 +338,7 @@ def main():
     parser.add_argument("-f", "--Fit", action='store_true', help='Build UniversalPayload file as UniversalPayload.fit', default=False)
     parser.add_argument('-l', "--LoadAddress", type=int, help='Specify payload load address', default =0x000800000)
     parser.add_argument('-c', '--DscPath', type=str, default="UefiPayloadPkg/UefiPayloadPkg.dsc", help='Path to the DSC file')
+    parser.add_argument('-ac', '--add_cc_flags', action='append', help='Add specified CC compile flags')
 
     args = parser.parse_args()