3.1b build fails on Cygwin due to wchar_t narrowing

[ridiculousfish]

Andrew Schulman reports on fish-users:

Hi. In Cygwin x86_64, the build fails with a bunch of "narrowing conversion
from ‘int’ to ‘wchar_t’" errors:


[51/113] /usr/bin/g++.exe  -DBINDIR=L\"/usr/bin\"
-DCMAKE_BINARY_DIR=\"fish-3.1b1-1.x86_64/build\"
-DCMAKE_SOURCE_DIR=\"fish-3.1b1-1.x86_64/src/fish-3.1b1\"
-DDATADIR=L\"/usr/share\" -DDOCDIR=L\"/usr/share/doc/fish\"
-DLOCALEDIR=\"/usr/sh
are/locale\" -DPREFIX=L\"/usr\" -DSYSCONFDIR=L\"/etc\" -D_REENTRANT
-D_UNICODE=1 -I. -Wno-comment -f
debug-prefix-map=fish-3.1b1-1.x86_64/build=/usr/src/debug/fish-3.1b1-1
-fdebug-prefix-map=fish-3.1b1-1.x86_64/src/fish-3.1b1=/usr/src/debug/fish-3.1b1-1
-fdiagnostics-color=always -Wall -Wextra -Wno-implicit-fallthrough
-Wno-comment -Wno-address -Wno-strict-aliasing -Wno-redundant-move  -O2 -g
-fno-exceptions -std=gnu++11 -MD -MT
CMakeFiles/fishlib.dir/src/fallback.cpp.o -MF
CMakeFiles/fishlib.dir/src/fallback.cpp.o.d -o
CMakeFiles/fishlib.dir/src/fallback.cpp.o -c
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/fallback.cpp
FAILED: CMakeFiles/fishlib.dir/src/fallback.cpp.o
/usr/bin/g++.exe  -DBINDIR=L\"/usr/bin\"
-DCMAKE_BINARY_DIR=\"fish-3.1b1-1.x86_64/build\"
-DCMAKE_SOURCE_DIR=\"fish-3.1b1-1.x86_64/src/fish-3.1b1\"
-DDATADIR=L\"/usr/share\" -DDOCDIR=L\"/usr/share/doc/fish\"
-DLOCALEDIR=\"/usr/share/locale\" -DPREFIX=L\"/usr\" -DSYSCONFDIR=L\"/etc\"
-D_REENTRANT -D_UNICODE=1 -I. -Wno-comment
-fdebug-prefix-map=fish-3.1b1-1.x86_64/build=/usr/src/debug/fish-3.1b1-1
-fdebug-prefix-map=fish-3.1b1-1.x86_64/src/fish-3.1b1=/usr/src/debug/fish-3.1b1-1
-fdiagnostics-color=always -Wall -Wextra -Wno-implicit-fallthrough
-Wno-comment -Wno-address -Wno-strict-aliasing -Wno-redundant-move  -O2 -g
-fno-exceptions -std=gnu++11 -MD -MT
CMakeFiles/fishlib.dir/src/fallback.cpp.o -MF
CMakeFiles/fishlib.dir/src/fallback.cpp.o.d -o
CMakeFiles/fishlib.dir/src/fallback.cpp.o -c
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/fallback.cpp
In file included from
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/fallback.cpp:268:0:
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/widecharwidth/widechar_width.h:45:1:
error: narrowing conversion of ‘983040’ from ‘int’ to ‘wchar_t’ inside { }
[-Wnarrowing]
};
^
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/widecharwidth/widechar_width.h:45:1:
error: narrowing conversion of ‘1048573’ from ‘int’ to ‘wchar_t’ inside { }
[-Wnarrowing]
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/widecharwidth/widechar_width.h:45:1:
error: narrowing conversion of ‘1048576’ from ‘int’ to ‘wchar_t’ inside { }
[-Wnarrowing]
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/widecharwidth/widechar_width.h:45:1:
error: narrowing conversion of ‘1114109’ from ‘int’ to ‘wchar_t’ inside { }
[-Wnarrowing]
fish-3.1b1-1.x86_64/src/fish-3.1b1/src/widecharwidth/widechar_width.h:57:1:
error: narrowing conversion of ‘69821’ from ‘int’ to ‘wchar_t’ inside { }
[-Wnarrowing]
...


There are also lots of warnings like:

fish-3.1b1-1.x86_64/src/fish-3.1b1/src/common.cpp:1307:34: warning:
comparison is always false due to limited range of data type
[-Wtype-limits]
                    if (0x10FFFF < max_val) max_val =
static_cast<wchar_t>(0x10FFFF);
                        ~~~~~~~~~^~~~~~~~~

and

At global scope:
cc1plus: warning: unrecognized command line option ‘-Wno-redundant-move’

[ridiculousfish]

Cherry-picked into Integration_3.1.0 as 4cee045

[andrew-schulman]

Confirmed that 7310619 fixes the build failure. Thanks.