Merge bitcoin/bitcoin#21593: build, qt, refactor: Get rid of some sed command instances

b95f7f8ac0 build, qt, refactor: Drop sed commands for win32-g++/qmake.conf (Hennadii Stepanov)

Pull request description:

  Such possibility is [available](https://codereview.qt-project.org/c/qt/qtbase/+/165348) since Qt 5.8.0.

ACKs for top commit:
  fanquake:
    ACK b95f7f8ac0

Tree-SHA512: e56a3d208a6bd5d42c722f8b344010fe7d1b6f7a28486613dfcb03f0403a47cee8476e2366eeaac401a19836cd09f782e8741a1e781ab4d78f72c500a30e4929

depends/packages/qt.mk

@@ -148,6 +148,9 @@ $(package)_config_opts_s390x_linux = -platform linux-g++ -xplatform bitcoin-linu
 $(package)_config_opts_mingw32 = -no-opengl
 $(package)_config_opts_mingw32 += -no-dbus
 $(package)_config_opts_mingw32 += -xplatform win32-g++
+$(package)_config_opts_mingw32 += "QMAKE_CFLAGS = '$($(package)_cflags) $($(package)_cppflags)'"
+$(package)_config_opts_mingw32 += "QMAKE_CXXFLAGS = '$($(package)_cflags) $($(package)_cppflags)'"
+$(package)_config_opts_mingw32 += "QMAKE_LFLAGS = '$($(package)_ldflags)'"
 $(package)_config_opts_mingw32 += -device-option CROSS_COMPILE="$(host)-"
 $(package)_config_opts_mingw32 += -pch
 
@@ -240,9 +243,6 @@ define $(package)_preprocess_cmds
   echo "!host_build: QMAKE_CFLAGS     += $($(package)_cflags) $($(package)_cppflags)" >> qtbase/mkspecs/common/gcc-base.conf && \
   echo "!host_build: QMAKE_CXXFLAGS   += $($(package)_cxxflags) $($(package)_cppflags)" >> qtbase/mkspecs/common/gcc-base.conf && \
   echo "!host_build: QMAKE_LFLAGS     += $($(package)_ldflags)" >> qtbase/mkspecs/common/gcc-base.conf && \
-  sed -i.old "s|QMAKE_CFLAGS           += |!host_build: QMAKE_CFLAGS            = $($(package)_cflags) $($(package)_cppflags) |" qtbase/mkspecs/win32-g++/qmake.conf && \
-  sed -i.old "s|QMAKE_CXXFLAGS         += |!host_build: QMAKE_CXXFLAGS            = $($(package)_cxxflags) $($(package)_cppflags) |" qtbase/mkspecs/win32-g++/qmake.conf && \
-  sed -i.old "0,/^QMAKE_LFLAGS_/s|^QMAKE_LFLAGS_|!host_build: QMAKE_LFLAGS            = $($(package)_ldflags)\n&|" qtbase/mkspecs/win32-g++/qmake.conf && \
   sed -i.old "s|QMAKE_CC                = \$$$$\$$$${CROSS_COMPILE}clang|QMAKE_CC                = $($(package)_cc)|" qtbase/mkspecs/common/clang.conf && \
   sed -i.old "s|QMAKE_CXX               = \$$$$\$$$${CROSS_COMPILE}clang++|QMAKE_CXX               = $($(package)_cxx)|" qtbase/mkspecs/common/clang.conf && \
   sed -i.old "s/LIBRARY_PATH/(CROSS_)?\0/g" qtbase/mkspecs/features/toolchain.prf