Fix /O2 regression on common code and typo'd CMAKE_C_FLAGS variables

The previous compile-options change moved /O2 from the global CMAKE_CXX_FLAGS_RELWITHDEBINFO to a target-specific COMPILE_OPTIONS on only `goldp` and `legoracers`. That dropped `common_goldp` and `common_legoracers` to no optimization, breaking match for any function in common code (e.g. GolFatalError 100% -> 15.58%, GolNameTable methods, GolImgFile, GolTgaFile).

Add common_goldp and common_legoracers to the same target list so they get the same /O2 / /Od / /Os config-dependent flags as goldp/legoracers.

Also fix the CMAKE_C_FLAGS_* variable references which had stray "XX" infixes ("CMAKE_C_FLAGSXX_DEBUG" instead of "CMAKE_CXX_FLAGS_DEBUG", etc.) — those expanded to empty strings and left the C compile flags effectively unset.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: foxtacles

CMakeLists.txt

@@ -452,10 +452,10 @@ if (MSVC_FOR_DECOMP)
   # Embed debug information (/Z7) for Debug and RelWithDebInfo configuration type
   set_property(TARGET goldp legoracers common_goldp common_legoracers PROPERTY MSVC_DEBUG_INFORMATION_FORMAT "$<$<CONFIG:Debug,RelWithDebInfo>:Embedded>")
 
-  set_property(TARGET goldp legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:Release,RelWithDebInfo>:/O2>")
-  set_property(TARGET goldp legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:Debug>:/Od>")
-  set_property(TARGET goldp legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:MinSizeRel>:/Os>")
-  set_property(TARGET goldp legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<NOT:$<CONFIG:Release,RelWithDebInfo,Debug,MinSizeRel>>:/Os>")
+  set_property(TARGET goldp legoracers common_goldp common_legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:Release,RelWithDebInfo>:/O2>")
+  set_property(TARGET goldp legoracers common_goldp common_legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:Debug>:/Od>")
+  set_property(TARGET goldp legoracers common_goldp common_legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<CONFIG:MinSizeRel>:/Os>")
+  set_property(TARGET goldp legoracers common_goldp common_legoracers APPEND PROPERTY COMPILE_OPTIONS "$<$<NOT:$<CONFIG:Release,RelWithDebInfo,Debug,MinSizeRel>>:/Os>")
 
   set(CMAKE_CXX_FLAGS "/W3 /GX /DWIN32 /D_WINDOWS")
   set(CMAKE_CXX_FLAGS_DEBUG "/Gm /D_DEBUG")
@@ -464,10 +464,10 @@ if (MSVC_FOR_DECOMP)
   set(CMAKE_CXX_FLAGS_MINSIZEREL "/DNDEBUG")
 
   set(CMAKE_C_FLAGS "${CMAKE_CXX_FLAGS}")
-  set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGSXX_DEBUG}")
-  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RXXELEASE}")
-  set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDXXEBINFO}")
-  set(CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSXXIZEREL}")
+  set(CMAKE_C_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG}")
+  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
+  set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
+  set(CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL}")
 
   set(CMAKE_EXE_LINKER_FLAGS "/machine:I386")
   set(CMAKE_EXE_LINKER_FLAGS_DEBUG "/incremental:yes /debug")