Compile and build tests with too many sections.

[Shankar Easwaran]

I have a test which generates too many sections and we expect the linker to   
resolve a COMMON symbol that exists in  multiple files.

Test :-

cat > gen.py << \!
for i in range (0, 90000):
    print "int foo%d() { return 0; }" % (i)
print "int mycommon[10];"
!

cat > gen2.py << \!
for i in range (0, 90000):
    print "int bar%d() { return 0; }" % (i)
print "int mycommon[20];"
!

python gen.py > gen.c
python gen2.py > gen2.c

g++ -c -ffunction-sections gen.c
g++ -c -ffunction-sections gen2.c
ld gen.o gen2.o
gen2.o:(.bss+0x0): multiple definition of `mycommon'
gen.o:(.bss+0x0): first defined here

Further analyzing the problem, it looks like ths symbol mycommon gets 
allocated in the section .bss as opposed to being a COMMON symbol.

Digging into the object file, When I see the generated file, the reserved 
section index SHN_COMMON gets used  up in the object file for symbols 
outside COMMON symbols.

Isnt the section indices defined by SHN_COMMON and few others really 
reserved, so when the ELF file is being written, ELF file should skip 
assigning reserved section numbers for symbols, and use the next available 
number ?