unify windows mkspecs: reorder variables and flags

Common changes to mingw-w64, ICC on Windows, and MSVC toolchains:
- set similar order of variables and its splitting into sections,
- set similar order of flags in variables and the way they are set.

mingw-w64 toolchain:
- move 'gcc-base.conf' include before setting Windows specific
  flags, similar to include 'msvc-desktop.conf' in ICC on Windows
  toolchain; this leads to consistency with other toolchains
  and allows to safely override common GCC variables with Windows
  specific ones, when needed,
- move 'QMAKE_EXT_OBJ' and 'QMAKE_EXT_RES' variables to the linker
  flags section, according to its purpose.

MSVC toolchain:
- set flags order in 'CONFIG' variable, similar to mingw-w64 toolchain.

Change-Id: I417cc8f7959c669dd504f2c5c11eb879a7989bd4
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

mkspecs/common/msvc-desktop.conf

@@ -15,7 +15,7 @@
 MAKEFILE_GENERATOR      = MSVC.NET
 QMAKE_PLATFORM          = win32
 QMAKE_COMPILER          = msvc
-CONFIG                 += incremental flat precompile_header autogen_precompile_source debug_and_release debug_and_release_target embed_manifest_dll embed_manifest_exe
+CONFIG                 += incremental flat debug_and_release debug_and_release_target precompile_header autogen_precompile_source embed_manifest_dll embed_manifest_exe
 DEFINES                += UNICODE _UNICODE WIN32
 QMAKE_COMPILER_DEFINES += _WIN32
 contains(QMAKE_TARGET.arch, x86_64) {
@@ -35,7 +35,7 @@ QMAKE_CFLAGS            = -nologo -Zc:wchar_t
 QMAKE_CFLAGS_WARN_ON    = -W3
 QMAKE_CFLAGS_WARN_OFF   = -W0
 QMAKE_CFLAGS_RELEASE    = $$QMAKE_CFLAGS_OPTIMIZE -MD
-QMAKE_CFLAGS_RELEASE_WITH_DEBUGINFO += $$QMAKE_CFLAGS_OPTIMIZE -MD -Zi
+QMAKE_CFLAGS_RELEASE_WITH_DEBUGINFO += $$QMAKE_CFLAGS_OPTIMIZE -Zi -MD
 QMAKE_CFLAGS_DEBUG      = -Zi -MDd
 QMAKE_CFLAGS_YACC       =
 QMAKE_CFLAGS_LTCG       = -GL
@@ -98,7 +98,6 @@ QMAKE_LIBS_OPENGL       = glu32.lib opengl32.lib gdi32.lib user32.lib
 QMAKE_LIBS_OPENGL_ES2   = gdi32.lib user32.lib
 QMAKE_LIBS_OPENGL_ES2_DEBUG = gdi32.lib user32.lib
 QMAKE_LIBS_COMPAT       = advapi32.lib shell32.lib comdlg32.lib user32.lib gdi32.lib ws2_32.lib
-
 QMAKE_LIBS_QT_ENTRY     = -lqtmain
 
 QMAKE_IDL               = midl /NOLOGO

mkspecs/win32-g++/qmake.conf

@@ -8,18 +8,17 @@
 #
 
 load(device_config)
+include(../common/gcc-base.conf)
 include(../common/g++-base.conf)
 
+# modifications to gcc-base.conf and g++-base.conf
+
 MAKEFILE_GENERATOR      = MINGW
 QMAKE_PLATFORM          = win32 mingw
 CONFIG                 += debug_and_release debug_and_release_target precompile_header
 DEFINES                += UNICODE _UNICODE
 QMAKE_COMPILER_DEFINES += __GNUC__ WIN32
 
-QMAKE_EXT_OBJ           = .o
-QMAKE_EXT_RES           = _res.o
-
-
 QMAKE_CC                = $${CROSS_COMPILE}gcc
 QMAKE_LEX               = flex
 QMAKE_LEXFLAGS          =
@@ -27,6 +26,7 @@ QMAKE_YACC              = bison -y
 QMAKE_YACCFLAGS         = -d
 QMAKE_CFLAGS           += -fno-keep-inline-dllexport
 QMAKE_CFLAGS_WARN_ON   += -Wextra
+
 QMAKE_CFLAGS_SSE2      += -mstackrealign
 
 QMAKE_CXX               = $${CROSS_COMPILE}g++
@@ -53,6 +53,8 @@ equals(QMAKE_HOST.os, Windows) {
     QMAKE_LINK_OBJECT_MAX = 10
     QMAKE_LINK_OBJECT_SCRIPT = object_script
 }
+QMAKE_EXT_OBJ           = .o
+QMAKE_EXT_RES           = _res.o
 QMAKE_PREFIX_SHLIB      =
 QMAKE_EXTENSION_SHLIB   = dll
 QMAKE_PREFIX_STATICLIB  = lib
@@ -78,6 +80,5 @@ QMAKE_OBJCOPY           = $${CROSS_COMPILE}objcopy
 QMAKE_NM                = $${CROSS_COMPILE}nm -P
 
 include(../common/angle.conf)
-include(../common/gcc-base.conf)
 
 load(qt_config)

mkspecs/win32-icc/qmake.conf

@@ -17,9 +17,10 @@ QMAKE_CC                = icl
 QMAKE_CFLAGS            = -nologo -Zm200 /Qprec /Qwd1744,1738,809,3373
 QMAKE_CFLAGS_WARN_ON    = -W3 /Qwd673
 QMAKE_CFLAGS_WARN_OFF   = -W0 /Qwd673
-QMAKE_CFLAGS_DEBUG      = -Zi -MDd -Od
+QMAKE_CFLAGS_DEBUG      = -Od -Zi -MDd
 QMAKE_CFLAGS_LTCG       = -Qipo
 QMAKE_CFLAGS_DISABLE_LTCG = -Qno-ipo
+
 QMAKE_CFLAGS_SSE2       = -QxSSE2
 QMAKE_CFLAGS_SSE3       = -QxSSE3
 QMAKE_CFLAGS_SSSE3      = -QxSSSE3