git commit --amend

Use __attribute__((malloc)) on memory allocation functions

This informs the C compiler that pointers returned from these functions
do not alias other functions, which allows it to do better code
optimization and should make the compiled code smaller.

References:
https://stackoverflow.com/a/53654773
https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-malloc-function-attribute
https://clang.llvm.org/docs/AttributeReference.html#malloc

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Closes #14827

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# Author:    Richard Yao <[email protected]>
# Date:      Fri May 26 18:47:52 2023 -0400
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