gcc: update to version 7.4.0, Add config options

for coping libc.a, libpthread.a and libstdc++ to target.
Add config option to eliminate need for -lstdc++ and -lgcc_pic
switches when linking statically

Signed-off-by: Noble Pepper <noblepepper@gmail.com>

devel/gcc/patches/900-bad-mips16-crt.patch

@@ -1,3 +1,24 @@
+commit 9dc38e48f7a6f88b7ac7bfaced91f53660204e46
+Author: Florian Fainelli <florian@openwrt.org>
+Date:   Fri Apr 5 12:36:06 2013 +0000
+
+    toolchain/gcc: .init and .fini need to pick one ISA
+    
+    The .init and .fini sections are built by concatenating code
+    fragments. Putting mips16 code in the middle of a mips32 code block
+    doesn't work. Make gcc built the magic crt stuff in no-mips16 mode.
+    
+    This is specific to 4.6-linaro but is probably portable to other gcc
+    flavors. Adding this to the t-libgcc-mips16 makefile fragment is a
+    hack not suitable for pushing upstream, but there is no mips/t-linux
+    or mips/t-uclibc and I am not going to touch gcc/configure for two
+    lines.
+    
+    Signed-off-by: Jay Carlson <nop@nop.com>
+    Signed-off-by: Florian Fainelli <florian@openwrt.org>
+    
+    SVN-Revision: 36200
+
 --- a/libgcc/config/mips/t-mips16
 +++ b/libgcc/config/mips/t-mips16
 @@ -43,3 +43,6 @@ SYNC_CFLAGS = -mno-mips16