mingw: remove msysGit/MSYS1 support

MSys has long fallen behind MSYS2 in features like Unicode or
x86_64 support or even security bug fixes, and is therefore no
longer used by anyone in the Git developer community. The Git for
Windows project itself started switching from MSys to MSYS2 early
in 2015, i.e. about eight years ago. Let's drop supporting MSys as
a development platform.

Signed-off-by: Harshil-Jani <harshiljani2002@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Harshil-Jani

config.mak.uname

@@ -623,6 +623,9 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
 	SHELL_PATH = /usr/coreutils/bin/bash
 endif
 ifeq ($(uname_S),MINGW)
+	ifeq ($(shell expr "$(uname_R)" : '1\.'),2)
+		$(error "Building with MSys is no longer supported")
+	endif
 	pathsep = ;
 	HAVE_ALLOCA_H = YesPlease
 	NO_PREAD = YesPlease
@@ -676,61 +679,43 @@ ifeq ($(uname_S),MINGW)
 	RC = windres -O coff
 	NATIVE_CRLF = YesPlease
 	X = .exe
-ifneq (,$(wildcard ../THIS_IS_MSYSGIT))
-	htmldir = doc/git/html/
-	prefix =
+	# MSys2
+	prefix = /usr/
+	# Enable DEP
+	BASIC_LDFLAGS += -Wl,--nxcompat
+	# Enable ASLR (unless debugging)
+	ifneq (,$(findstring -O,$(filter-out -O0 -Og,$(CFLAGS))))
+		BASIC_LDFLAGS += -Wl,--dynamicbase
+	endif
+	ifeq (MINGW32,$(MSYSTEM))
+		prefix = /mingw32
+		HOST_CPU = i686
+		BASIC_LDFLAGS += -Wl,--pic-executable,-e,_mainCRTStartup
+	endif
+	ifeq (MINGW64,$(MSYSTEM))
+		prefix = /mingw64
+		HOST_CPU = x86_64
+		BASIC_LDFLAGS += -Wl,--pic-executable,-e,mainCRTStartup
+	else
+		COMPAT_CFLAGS += -D_USE_32BIT_TIME_T
+		BASIC_LDFLAGS += -Wl,--large-address-aware
+	endif
+	CC = gcc
+	COMPAT_CFLAGS += -D__USE_MINGW_ANSI_STDIO=0 -DDETECT_MSYS_TTY \
+		-fstack-protector-strong
+	EXTLIBS += -lntdll
 	INSTALL = /bin/install
-	EXTLIBS += /mingw/lib/libz.a
 	INTERNAL_QSORT = YesPlease
 	HAVE_LIBCHARSET_H = YesPlease
-	NO_GETTEXT = YesPlease
-	NO_PYTHON = YesPlease
-	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS
-else
-	ifneq ($(shell expr "$(uname_R)" : '1\.'),2)
-		# MSys2
-		prefix = /usr/
-		# Enable DEP
-		BASIC_LDFLAGS += -Wl,--nxcompat
-		# Enable ASLR (unless debugging)
-		ifneq (,$(findstring -O,$(filter-out -O0 -Og,$(CFLAGS))))
-			BASIC_LDFLAGS += -Wl,--dynamicbase
-		endif
-		ifeq (MINGW32,$(MSYSTEM))
-			prefix = /mingw32
-			HOST_CPU = i686
-			BASIC_LDFLAGS += -Wl,--pic-executable,-e,_mainCRTStartup
-		endif
-		ifeq (MINGW64,$(MSYSTEM))
-			prefix = /mingw64
-			HOST_CPU = x86_64
-			BASIC_LDFLAGS += -Wl,--pic-executable,-e,mainCRTStartup
-		else
-			COMPAT_CFLAGS += -D_USE_32BIT_TIME_T
-			BASIC_LDFLAGS += -Wl,--large-address-aware
-		endif
-		CC = gcc
-		COMPAT_CFLAGS += -D__USE_MINGW_ANSI_STDIO=0 -DDETECT_MSYS_TTY \
-			-fstack-protector-strong
-		EXTLIBS += -lntdll
-		INSTALL = /bin/install
-		INTERNAL_QSORT = YesPlease
-		HAVE_LIBCHARSET_H = YesPlease
-		USE_GETTEXT_SCHEME = fallthrough
-		USE_LIBPCRE = YesPlease
-		USE_NED_ALLOCATOR = YesPlease
-		ifeq (/mingw64,$(subst 32,64,$(prefix)))
-			# Move system config into top-level /etc/
-			ETC_GITCONFIG = ../etc/gitconfig
-			ETC_GITATTRIBUTES = ../etc/gitattributes
-		endif
-	else
-		COMPAT_CFLAGS += -D__USE_MINGW_ANSI_STDIO
-		NO_CURL = YesPlease
-		NO_PYTHON = YesPlease
+	USE_GETTEXT_SCHEME = fallthrough
+	USE_LIBPCRE = YesPlease
+	USE_NED_ALLOCATOR = YesPlease
+	ifeq (/mingw64,$(subst 32,64,$(prefix)))
+		# Move system config into top-level /etc/
+		ETC_GITCONFIG = ../etc/gitconfig
+		ETC_GITATTRIBUTES = ../etc/gitattributes
 	endif
 endif
-endif
 ifeq ($(uname_S),QNX)
 	COMPAT_CFLAGS += -DSA_RESTART=0
 	EXPAT_NEEDS_XMLPARSE_H = YesPlease